PaparazziUAV - User contributions [en]

RC Receivers and Radios

2014-10-03T13:17:11Z

Hwarm: /* PCM Receivers */

= Introduction=

To be able to test your airframe before it flies fully autonomous a regular RC transmitter in combination with a receiver can be used. This is essential for testing and tuning your airframe. For this to work the received steering commands have to leave the receiver. Only then with this flow of command data the autopilot when flown in manual mode can do something you tell it to. This page is to give you information of how to connect various receivers. Also how to modify receiver so they can talk to the autopilot.

=Setup=

Once you have physically connected your receiver we need to setup the transmitter and receiver combination correctly. This can be an complex task due to the overwhelming amount of options. [[rc_transmitter_and_receiver_setup| To assist you in this setup quest a specific wiki page]] is available to help you out.

If you have a new Graupner HOTT system, the [[Graupner_HOTT_setup]] page will provide all key informations about setting up the Graupner components (Transmitter/Receiver to output a ppm sum stream).

=2.4GHz Receivers=

There are three ways you can connect a 2.4GHz system to your Autopilot:
# PPM Sum stream (should be supported on all current autopilot boards)
# Spektrum (with data and bind pin, also dual satelite use is possible on some boards)
# Futaba SBUS

If you come across the term "Satellite Receiver", it has nothing to do with satellites in earth orbit. It is just a term to describe an auxiliary receiver normally used to improve reception by plugging into the 'main' receiver.

If your receiver can not output one of the signals above, maybe you need following:

# Must have combined PPM pulsetrain out or use [[PPM_Encoder | PPM Encoder]] board. See the [[Get_Hardware| Get Hardware]] page for links to suppliers)
# At least one extra channel beyond those needed to control the servos and motor. (throttle-roll-pitch-mode)

==Graupner GR-12/GR-16/GR-20 HOTT==

GR-12/GR-16/GR-20 are Transmitters from the [http://www.graupner.de/en/products/1736df13-32af-4183-aa8e-80f31a7f03cb/productcategory.aspx Graupner HOTT Series].

* 2.4 GHz FHSS system
* regular software updates, good support
* different languages (also with voice output)
* receivers work with 3.6 V to 8.4 V (functional down to 2.5 V)
* highly adjustable

For a detailed instructions for updates and setup look at the [[Graupner_HOTT_setup]] page.

==Orange CPPM RX==

[[Image:Orange_RX_615_with_CPPM.jpg|thumb|left|Orange R615X Receiver]]

OrangeRx R615X DSM2/DSMX Compatible 6Ch 2.4GHz Receiver with CPPM out. A nice solution for e.g. Tiny and TWOG autopilot boards. Use modern DSMX and your trusty AP board.

 

==Orange Satellite RX==

[[Image:Orangerx_satellite_receiver.jpg|thumb|left|OrangeRx R100 Receiver]]

OrangeRx R100 Satellite Receiver [http://www.hobbyking.com/hobbyking/store/__13418__OrangeRx_R100_Satellite_Receiver.html| R100SAT]. Works well, simple to connect, do not expect long range wonders however. Although called, "Satellite Receiver" it is usable as a ful blown receiver when connected to an AP board

OrangeRx R110X Satellite Receiver [http://www.hobbyking.com/hobbyking/store/__38393__OrangeRx_R110X_2_4Ghz_DSMX_Satellite_Receiver.html| R110X]. Great, simple to connect, and is DSMX capable, really advised over the R100
 

==Spektrum 9645==

[[Image:Spektrum_9645_satellite_receiver.jpg|thumb|left|Spektrum 9645 satellite receiver]]

[http://www.spektrumrc.com/Products/Default.aspx?ProdID=SPM9645| Spektrum 9645 satellite receiver]. Works well, simple to connect. the DSMX mode is not used, it is used in the DSM2 mode, the receiver is backards compatible with that protocol.
 

==Futaba FASST 7-channel receiver==

[[Image:rs617fasst.jpg|thumb|left|Futaba RS 617]]

* Pin 8 (upper right corner in picture) of the small IC on the right contains 5 PPM pulses and can go directly to paparazzi. Pulse 6 and 7 go directly to the servos.
* Best is to remove the resistors of one of the channels and connect a small wire to pin 8 to get the combined 5 pulses on the robust 1/10th inch header.
* Do not forget to use channel 3 (only failsafe channel) as mode switch with fail safe "throttle off" as mode 2.
 

==Robbe RASST 7 & 8 channel receivers==

Robbe has produced line of Futaba FASST compatible receivers that can output only PPM which results ablility to plug into autopilot without encoder.
* [http://www.robbe.de/empfaenger-r-6007-sp-2-4-g-rasst.html R6007SP 2,4 GHz RASST] - 7 channel, for small aircraft
* [http://www.robbe.de/empf-r6107sp-2-4-ghz-rasst.html R6107SP 2,4 GHz RASST] - 7 channel, >1000m range
* [http://www.robbe.de/empf-r6008sp-2-4-ghz-rasst.html R6008SP 2,4 GHz RASST] - 8 channel, upto 3000m range

===Switch Assignment===

To assign the three position switch to any other channel but channel 7 follow these steps:
# Set up aux2(refers to aux2 on rx not the switch on the tx. aka ch7) with its input selected as 3 pos switch.
# Set up this mix - Gear to Gear (Up=-100, Down=-100, Offset =0). This inhibits the gear switch.
# Set up another mix - Aux2 to Gear (Up=100, Down=100, Offset = 0).
Notes:
#Gear on a DX-7 Air is Channel 5 and AUX2 is CH7. Once again i am referring to the inputs which are labeled on the RX not what the switches are named on the TX. If your using a DX-7 heli please substitute the names for what the rx channels are named into this guide
# DX7 Heli the 3-pos switch is named "flight mode"
# DX7 Air the 3-pos switch is named "flaps"

===Failsafe Setup===

To set up the mode channel (3 pos switch) to default to auto2 if connection is lost between rx and tx follow these steps:
# Put 3 position Switch into AUTO2 Position
# Put in bind plug
# Power up
# REMOVE the bind plug
# Power up Tx while pushing bind button
# Wait until light becomes steady and not blinking (it may become steady right off but will then start blinking again so let it go at least 5 seconds)

==Jeti Duplex 2.4 GHz Receiver Rsat 2==

[[Image:Jeti_Duplex_Rsat2.jpg|thumb|left|Jeti RSat 2]]
* Outputs PPM, no soldering or PPM board required
* Only 12 gramms
* Full duplex technology provides safe radio link and redundant telemetry to standard paparazzi telemetry.
* [http://www.jetimodel.cz/index.php?page=products&old=0&category=4 Transmitter module] can be installed in any receiver.

More information can be found a the [http://www.jetimodel.cz/index.php?page=product&id=165 Homepage of Jeti] and the [http://www.mikrokopter.de/ucwiki/JetiDuplex MikroKopter Wiki].
 

==DT Receiver DSN2 Rx31c 7ch SumPPM==

[[Image:rc31b.jpg|thumb|left|DT Receiver Rx31c 7ch SumPPM]]

* Outputs PPM,with 7 chanels for Spectrum DX8 and DX6
* subminiature receiver with full rage. It has only 0.21 grams. Cost abut 30 Euros.
* The solution for very small aircraft.
* Order for the channels with Spectrum DX8 in accro mode: Throttle, Roll,Pitch, Gear, Mix, Flap,Aux2
[http://www.deltang.co.uk/rx31b.htm]
[http://www.lipoly.de/index.php?main_page=product_info&cPath=3701_264_272_2861_3214&products_id=259971]

=PCM Receivers=

Most of the known PCM transmitter also can be set to PPM mode. If this is set, then the regular description for PPM applies since the PCM receiver like a JR/Gaupner SMC16 Scan can output PPM perfectly.

However if setting up you transmitter to PPM out then the following applies:

# Must use ppm encoder board. (See [[Get_Hardware|Get Hardware]] page for suppliers)
# At least one extra channel beyond those needed to control the servos and motor.

= PPM Receivers =

To use a 26/27/35/40/41/72/ MHz receiver a few requirements are necessary

# At least one extra channel beyond those needed to control the servos and motor.
# A receiver or modified receiver which outputs a full ppm signal.

== R/C Receiver Interface==

All versions of the Paparazzi autopilot include a connector to interface with a standard R/C receiver for manual or semi-autonomous control during the testing and tuning phases. Two interface options exist:
# Tap into the PPM signal running between the RF section and the servo driver of your receiver and route it to the Paparazzi. Let the Paparazzi generate individual servo signals and connect all servos directly to the autopilot. This method requires only 3 wires to the receiver (power and PPM), is compatible with all Paparazzi autopilots, and provides 8 manual R/C channels and the potential for more autonomous channels regardless of the capability of the R/C receiver.
# Cut the PPM trace and route it thru the autopilot and back to the receiver, using the servo driver IC on your R/C receiver to drive the servos. This option requires 4 wires (Ground, PPM-in, PPM-out, Reset) and your receiver must have a supported servo driver IC. This allows you to use the large servo connectors on your R/C receiver and does not require any modification to your servos or ESC but does require you to cut a trace on your R/C receiver and limits the number of servos to the capacity of your receiver. Compatible with Classix and Tiny 1.1.
# Note that on the Classix the PPM_in pin is FOO2...

Note 1: Exact value not critical. Depending on RC Transmitter type & Manufacturer. 
Note 2: Depending on Transmitter number of Channels and t,,n,, durations. 
Note 3: Not critical. Depending on Synchro detection method.]]

<gallery>
Image:RC_Receiver_Timing_Diagram.jpg||PPM Timing Diagram
Image:RC_Receiver_Tiny.jpg|3-Wire setup, driving servos from the autopilot
Image:RC_Receiver_classix.jpg|4-Wire setup, driving servos from the R/C receiver
</gallery>
 

=== Common demux chips ===

Typical used chips are the cmos [http://www.doctronics.co.uk/4015.htm 4015] and [http://www.doctronics.co.uk/4017.htm 4017].

The 4015 uses either pin 1 or pin 9 for the clock and the input is on 7 and 15. The 4017 has just one shift register and has its clock input on pin 14 and the enable on pint 13.

In most receivers you are after the clock; though some may be pulsed; in which case you need the enable. Note that the 4017 enable has inverted logic (low to be enabled) whereas the input on the 4015 can be either (typically high). If the enable pin is held low (4017) or if the input pin (4015) is held high always;e.g. connected to the ground or the Vcc - then it is fair to assume that the PPM signal is most propably on the clock input.

== 35/40Mhz RC Receivers ==

Note that there is information on modifying other receiver models at [http://mikrokopter.de/ucwiki/RC-Empf%C3%A4nger mikrokopter.de]. It's in German however the pictures contain most of the information or use google translate.
Shielded wire is recommended for receiver and autopilot connection, as unshielded one may cause noise in receiver.

=== Futaba FP-R116FB 6 Channel FM 35MHz receiver ===

[[Image:Rc_fut_web.jpg|thumb|left|Wiring of a Futaba R136]]
*Orange wire is connected to PPM signal
*Red wire is connected to VCC
*Brown wire is connected to GND
 

=== Futaba R136F 6 Channel FM receiver ===

[[Image:rx_futaba136.jpg|thumb|left|Wiring of a Futaba R136]]
*41 MHz
*White wire is connected to PPM signal
 

=== Futaba R168DF 8 Channel dual FM receiver ===

[[Image:rx_futaba168df.jpg|thumb|left|Wiring of a Futaba R168DF]]
*35 MHz
*PPM wire is connected to 862 receiver pin on the board. VCC and GND is on the 8/B original position.
 

=== ACT Micro-6 FM receiver ===

[[Image:rx_act_micro-6.jpg|thumb|left|Wiring of a ACT Micro-6]]
*Available in 35 or 40 MHz versions
*White wire is connected to PPM signal
*[http://www.acteurope.com/Micro_6anl.pdf Datasheet (German)]
 

=== ACT DSL-4top [http://www.mikrokopter.de/ucwiki/DSL4top mikrokopter.de] version ===

[[Image:DSL4top.jpg|thumb|left|DSL-4top mikrokopter.de version]]
* Special version for mikrokopter.de - Only available in their [https://www.mikrocontroller.com/index.php?main_page=product_info&products_id=215&zenid=8ce8bab70f3e9d684e01f724316d9690 shop]!
* '''Outputs PPM directly''' on the channel 1 connector!
* No soldering necessary
* ACT Lifetime warranty
* Sells for ~45 euro
 

=== Futaba R115F 5 Channel FM receiver ===

[[Image:pprz_rx115.jpg|thumb|left|Wiring of a Futaba R115]]
*Available in 35 and 40 MHz versions
*White wire is connected to PPM signal
 

=== JETI REX 5 plus (no MPD) receiver ===

[[Image:520_Jeti_5_plus.jpg|thumb|left|Wiring of a REX 5]]

*Popular Czech made micro r/c receiver, available in 35 or 40 MHz versions
*´folded´ PCB design with parts inside, mostly inaccessable
*Small grey wire is connected to via with PPM signal
*Unusual connector used for testing, soldering recommended
*shielded wire recommended, this one taken from PC parts recycling (former soundcard to m/b connector cable)
*[http://www.jetimodel.cz/eng/navody_en/rex5_eng.pdf Datasheet (English)]
 
[[Image:DSC02414.JPG|thumb|left|other Layout of REX 5]]

=== Receiver RX-7-SYNTH IPD receiver [http://www.multiplex-rc.de/hp/produkte/artikel_detail.jsp?lfdnr=55880&action=add2notice&qty=1&cachenepper=1227896925116 Multiplex-rc.de] ===

[[Image:RX-7-SYNTH_IPD.jpg|thumb|left|Wiring of RX-7-SYNTH IPD]]

*Available in 35, 36 and 40 MHz versions
*A compact, high-quality 7-channel single-conversion FM / PPM IPD receiver
*Easy modification through connectors, see pictures
 

=== Protech 5FM 35 mHz Receiver ===

The low cost Protech '5FM' receiver makes use of an SMD version of the standard 74AHC164[http://www.ic-on-line.cn/IOL/datasheet/74ahct164_18057.pdf] 8 bit shift register; you are after PIN 1 of this chip. The circuit board has a testpad for just this pin at the top side of the circuit board.

<gallery>
Image:protech-5fm.jpg|Figure 1. Protech 5FM 35 mHZ Receiver, mark 2
Image:protech-5fm-pad.jpg|Figure 2. PPM tap location for the Protech 5FM receiver, near the 74AHC164 shift register
Image:protech-5fm-scope.jpg|Figure 3. Protech 5FM PPM signal - not very clean/digital
</gallery>

Two physical versions exist; the older one [http://www.protech.be/Manuals/PRO205manual%20web.pdf] and a newer one pictured (fig 1). It has been distributed by protech with various ready-to-fly planes; such as the Skyraider[http://www.modelbouwforum.nl/forums/beginners/50677-protech-skyraider.html].

The solder/testpad you are after the one right next the 74x164 chip its pin 1. In this image it has a jellow wire soldered to it (the yellow wire at the top left is the normal antenna connector (fig 2). Note however that the signal is not very clean (1v/div) - which may cause issues - as shown in the above image (fig 3).

This is further compunded by the relatively noisy electrical engines; which are not brushless. A ferrite coil does not seem to help enough - Papparazi and GPS loose sync often through Xbee. Replacing the engine by a brushless outrunnen resolve the issue completely.

=== Profi Penta 35 MHz ===

<gallery>
Image:DSC00547.JPG
Image:DSC00545.JPG
</gallery>

=== Graupner R16Scan ===

The Graupner R16Scan and SMC16Scan are available in 35,36,40,41Mhz versions and belongs to one of the most reliable traditional receivers in it's class. It's a highly selective PLL SCAN narrow-band FM superhet receiver. Has 8 servo connections. And the best thing; No crystals swap is required with this receiver since it scans for your TX transmission frequency. Modified for PPM output, it can output 9 separate channels.

To modify this receiver for use with an autopilot some soldering on tiny IC pins is needed. No additional electronic parts needed.

# Desolder existing resistor from IC pin, fast and carefully
# solder a short wire to the pin on the other side of the IC as on the picture, preferably als put some isolation over it
# Solder this wire to the resistor, move isolation over resistor
# Use a little UHU por glue to make sure nothing moves when flying in rought conditions

The PPM combined data is now available on connector 8. You still can power the receiver seperatly via + - pins if you want to. Or straight from the AP board 5v out.

<gallery>
Image:Graupner_R16Scan_pwm_modification_01.jpg|How to modify
Image:Graupner_R16Scan_pwm_modification_02.jpg|Modification from other side
Image:Graupner_R16Scan_pwm_modification_03.jpg|Modification Closeup
Image:Graupner_R16Scan_pwm_modification_04.jpg|Well... why not change them all in one go.
</gallery>

== 72Mhz Receivers ==

=== Castle Creations [http://www.castlecreations.com/products/berg_ms4l.html Berg 4L] ===

[[Image:berg4L.jpg|thumb|left|Wiring of a Berg 4L]]
* Expect fantastic performance from these $40 USD parts but be warned that they are known to have unreliable crystal sockets and brittle antenna wire. The ''Berg 7'' channel receiver should work equally well and is known to have a better crystal socket - note that either receiver will provide '''8 channels''' in manual R/C mode when used with Paparazzi. Note: the rugged ''Berg 4'' cannot be modified, only the ''Berg 4L'' and ''Berg 7''.

To Modify a Berg4L, follow these instructions:
# Remove the shrink wrap. Use a good knife and be careful to not damage any of the components on the receiver. I would recommend that you cut on the sides (edge of the PCB) to be sure to avoid damaging the shielding
# Desolder the headers. We will not use them with tiny AP as the servos are connected directly to the AP. This is pretty easy to do when you have a hot air rework station. If you don't have one, your best bet is to cut the header off and remove the left over pins one by one with a regular iron. There is a piece of shielding material that is connected to one of the ground pins of the header. You need to remove it carefully from the header without damaging it and re-solder it to the gnd pad.
# You need to solder 3 wires to the receiver. Gnd, +5V and PPM. To locate the PPM signal, first locate the PIC micro controller close to the location of the headers. The PPM signal is on the corner pin closest to the corner of the receiver. Soldering a 28guage wire directly to the PIN isn't very difficult. For the power connection, use the pads that were used for the header. The outside pin is Gnd, the second pin is +5V. What I did is solder the wires on the pad going straight down, then I looped the 3 wires 360 degrees and glued them to the PCB with hot glue. This provides good strain relief.
# While you have the PCB in your hands, take the opportunity to remove the crystal connector and solder your crystal directly to the PCB for added reliability.
# I also used some hot glue to add more strain relief to the antenna
# Use some large shrink wrap to cover the entire receiver again
 

=== Hitec Electron 6 72MHz Reciever ===

This was written for MNAV from crossbow but is still usable with PPRZ.

[[Image:Electron6mod.jpg|thumb|left]]
 

=== Corona Synthesized Dual-Conv Receiver 8Ch ===

[http://www.corona-rc.com/coproductshowE.asp?ArticleID=63 manual]

This receiver is available in 27,35,36,40,72 mhz and a Synthesized receiver, meaning you do not need to change frequency crystals.

How to modify for combined signal

# Cut the 8th channel PWM output pin near the PCB.
# Connected a pin from the Atmel (see picture) to the 8th channel PWM signal. (optionally, weaving the wire through some holes on the board.) Make sure you have a fine tip on your soldering iron and a magnifying glass strapped to your head!
# Glue the wire down (CA works)
# Be sure to glue the pin that you cut in place (previously, being soldered to the board was holding the pin in place)

It is maybe possible to reprogram the atmel with your own firmware. If you succeed in this plz add relevant info here.

That pin provides a 1V to 2V signal, it works with the PPRZ, although its a bit gittery (the slew rate is not real good).
<gallery>
Image:Corona_Synthesized_Receiver_72Mhz_bottom.jpg
Image:Corona_Synthesized_Receiver_72Mhz_top.jpg
Image:Corona_Synthesized_Receiver_72Mhz_top_atmel.jpg
</gallery>
 

= UHF Receivers =

Note that in most countries an amateur radio license is required to use 433MHz UHF. 
See also [[Modems#HAM_.2F_CEPT_Licence]].

== Scherrer UHF ==

[[Image:ScherrerUHF.jpg|thumb|left|Scherrer UHF Rx]]

The [http://www.webx.dk/rc/uhf-link3/uhf-link3.htm Scherrer UHF] is a high quality diversity radio control system. It has a PPM output and can be connected directely to Paparazzi. A ppm encoder board is not required. It has an RSSI output.
 

== ImmersionRC EzUHF ==

[[Image:EzUHFTx.jpg|thumb|left|ImmersionRC Tx]]

The [http://www.immersionrc.com/products.htm ImmersionRC EzUHF] is a high quality diversity radio control system. The recent firmwares have a PPM output on Ch. 1, but this needs to be activated through the PC configuration software with the proper firmware loaded. It connects directly to EzOSD and the TrackR2 which enables RSSI monitoring and head tracking for FPV.

Some people had issues with the exact timing, where the ROLL channel disappeared. If the radio has more than 6 channels, there may be methods to slave another channel to the roll channel (usually for the operation of dual ailerons). The ezuhf configuration file is using this method, where channel 1 is copied to channel 6. The EzUHF modules receive the PPM output stream from the radio and need to interpret it. For this reason, the ezuhf configuration file should be verified for proper functioning and you may find that channels are remapped to others with different purposes.

Search "sander style" antennas for a way to build your own cheap, high-quality antennas for these rx modules and which provide a range well beyond the horizon.

See [http://www.immersionrc.com/EzUHF.htm EzUHF manual+firmware] for more information.
 

[[Category:Hardware]] [[Category:User_Documentation]]

RC Receivers and Radios

2014-10-03T13:16:20Z

Hwarm: /* PCM Receivers */

2014-10-03T13:04:47Z

Hwarm:

RC Receivers and Radios

2014-10-03T13:03:09Z

Hwarm:

= Introduction=

To be able to test your airframe before it flies fully autonomous a regular RC transmitter in combination with a receiver can be used. This is essential for testing and tuning your airframe. For this to work the received steering commands have to leave the receiver. Only then with this flow of command data the autopilot when flown in manual mode can do something you tell it to. This page is to give you information of how to connect various receivers. Also how to modify receiver so they can talk to the autopilot.

=Setup=

Once you have physically connected your receiver we need to setup the transmitter and receiver combination correctly. This can be an complex task due to the overwhelming amount of options. [[rc_transmitter_and_receiver_setup| To assist you in this setup quest a specific wiki page]] is available to help you out.

If you have a new Graupner HOTT system, the [[Graupner_HOTT_setup]] page will provide all key informations about setting up the Graupner components (Transmitter/Receiver to output a ppm sum stream).

=2.4GHz Receivers=

There are three ways you can connect a 2.4GHz system to your Autopilot:
# PPM Sum stream (should be supported on all current autopilot boards)
# Spektrum (with data and bind pin, also dual satelite use is possible on some boards)
# Futaba SBUS

If you come across the term "Satellite Receiver", it has nothing to do with satellites in earth orbit. It is just a term to describe an auxiliary receiver normally used to improve reception by plugging into the 'main' receiver.

If your receiver can not output one of the signals above, maybe you need following:

# Must have combined PPM pulsetrain out or use [[PPM_Encoder | PPM Encoder]] board. See the [[Get_Hardware| Get Hardware]] page for links to suppliers)
# At least one extra channel beyond those needed to control the servos and motor. (throttle-roll-pitch-mode)

==Graupner GR-12/GR-16/GR-20 HOTT==

GR-12/GR-16/GR-20 are Transmitters from the [http://www.graupner.de/en/products/1736df13-32af-4183-aa8e-80f31a7f03cb/productcategory.aspx Graupner HOTT Series].

* 2.4 GHz FHSS system
* regular software updates, good support
* different languages (also with voice output)
* receivers work with 3.6 V to 8.4 V (functional down to 2.5 V)
* highly adjustable

For a detailed instructions for updates and setup look at the [[Graupner_HOTT_setup]] page.

==Orange CPPM RX==

[[Image:Orange_RX_615_with_CPPM.jpg|thumb|left|Orange R615X Receiver]]

OrangeRx R615X DSM2/DSMX Compatible 6Ch 2.4GHz Receiver with CPPM out. A nice solution for e.g. Tiny and TWOG autopilot boards. Use modern DSMX and your trusty AP board.

 

==Orange Satellite RX==

[[Image:Orangerx_satellite_receiver.jpg|thumb|left|OrangeRx R100 Receiver]]

OrangeRx R100 Satellite Receiver [http://www.hobbyking.com/hobbyking/store/__13418__OrangeRx_R100_Satellite_Receiver.html| R100SAT]. Works well, simple to connect, do not expect long range wonders however. Although called, "Satellite Receiver" it is usable as a ful blown receiver when connected to an AP board

OrangeRx R110X Satellite Receiver [http://www.hobbyking.com/hobbyking/store/__38393__OrangeRx_R110X_2_4Ghz_DSMX_Satellite_Receiver.html| R110X]. Great, simple to connect, and is DSMX capable, really advised over the R100
 

==Spektrum 9645==

[[Image:Spektrum_9645_satellite_receiver.jpg|thumb|left|Spektrum 9645 satellite receiver]]

[http://www.spektrumrc.com/Products/Default.aspx?ProdID=SPM9645| Spektrum 9645 satellite receiver]. Works well, simple to connect. the DSMX mode is not used, it is used in the DSM2 mode, the receiver is backards compatible with that protocol.
 

==Futaba FASST 7-channel receiver==

[[Image:rs617fasst.jpg|thumb|left|Futaba RS 617]]

* Pin 8 (upper right corner in picture) of the small IC on the right contains 5 PPM pulses and can go directly to paparazzi. Pulse 6 and 7 go directly to the servos.
* Best is to remove the resistors of one of the channels and connect a small wire to pin 8 to get the combined 5 pulses on the robust 1/10th inch header.
* Do not forget to use channel 3 (only failsafe channel) as mode switch with fail safe "throttle off" as mode 2.
 

==Robbe RASST 7 & 8 channel receivers==

Robbe has produced line of Futaba FASST compatible receivers that can output only PPM which results ablility to plug into autopilot without encoder.
* [http://www.robbe.de/empfaenger-r-6007-sp-2-4-g-rasst.html R6007SP 2,4 GHz RASST] - 7 channel, for small aircraft
* [http://www.robbe.de/empf-r6107sp-2-4-ghz-rasst.html R6107SP 2,4 GHz RASST] - 7 channel, >1000m range
* [http://www.robbe.de/empf-r6008sp-2-4-ghz-rasst.html R6008SP 2,4 GHz RASST] - 8 channel, upto 3000m range

===Switch Assignment===

To assign the three position switch to any other channel but channel 7 follow these steps:
# Set up aux2(refers to aux2 on rx not the switch on the tx. aka ch7) with its input selected as 3 pos switch.
# Set up this mix - Gear to Gear (Up=-100, Down=-100, Offset =0). This inhibits the gear switch.
# Set up another mix - Aux2 to Gear (Up=100, Down=100, Offset = 0).
Notes:
#Gear on a DX-7 Air is Channel 5 and AUX2 is CH7. Once again i am referring to the inputs which are labeled on the RX not what the switches are named on the TX. If your using a DX-7 heli please substitute the names for what the rx channels are named into this guide
# DX7 Heli the 3-pos switch is named "flight mode"
# DX7 Air the 3-pos switch is named "flaps"

===Failsafe Setup===

To set up the mode channel (3 pos switch) to default to auto2 if connection is lost between rx and tx follow these steps:
# Put 3 position Switch into AUTO2 Position
# Put in bind plug
# Power up
# REMOVE the bind plug
# Power up Tx while pushing bind button
# Wait until light becomes steady and not blinking (it may become steady right off but will then start blinking again so let it go at least 5 seconds)

==Jeti Duplex 2.4 GHz Receiver Rsat 2==

[[Image:Jeti_Duplex_Rsat2.jpg|thumb|left|Jeti RSat 2]]
* Outputs PPM, no soldering or PPM board required
* Only 12 gramms
* Full duplex technology provides safe radio link and redundant telemetry to standard paparazzi telemetry.
* [http://www.jetimodel.cz/index.php?page=products&old=0&category=4 Transmitter module] can be installed in any receiver.

More information can be found a the [http://www.jetimodel.cz/index.php?page=product&id=165 Homepage of Jeti] and the [http://www.mikrokopter.de/ucwiki/JetiDuplex MikroKopter Wiki].
 

==DT Receiver DSN2 Rx31c 7ch SumPPM==

[[Image:rc31b.jpg|thumb|left|DT Receiver DSN2 Rx31c 7ch SumPPM]]

* Outputs PPM,with 7 chanels for Spectrum DX8 and DX6
* subminiature receiver with full rage. It has only 0.21 grams. Cost abut 30 Euros.
* The solution for very small aircraft.
* Order for the channels with Spectrum DX8 in accro mode: Throttle, Roll,Pitch, Gear, Mix, Flap,Aux2
* [http://www.deltang.co.uk/rx31b.htm]
*[http://www.lipoly.de/index.php?main_page=product_info&cPath=3701_264_272_2861_3214&products_id=259971]

=PCM Receivers=

Most of the known PCM transmitter also can be set to PPM mode. If this is set, then the regular description for PPM applies since the PCM receiver like a JR/Gaupner SMC16 Scan can output PPM perfectly.

However if setting up you transmitter to PPM out then the following applies:

# Must use ppm encoder board. (See [[Get_Hardware|Get Hardware]] page for suppliers)
# At least one extra channel beyond those needed to control the servos and motor.

= PPM Receivers =

To use a 26/27/35/40/41/72/ MHz receiver a few requirements are necessary

# At least one extra channel beyond those needed to control the servos and motor.
# A receiver or modified receiver which outputs a full ppm signal.

== R/C Receiver Interface==

All versions of the Paparazzi autopilot include a connector to interface with a standard R/C receiver for manual or semi-autonomous control during the testing and tuning phases. Two interface options exist:
# Tap into the PPM signal running between the RF section and the servo driver of your receiver and route it to the Paparazzi. Let the Paparazzi generate individual servo signals and connect all servos directly to the autopilot. This method requires only 3 wires to the receiver (power and PPM), is compatible with all Paparazzi autopilots, and provides 8 manual R/C channels and the potential for more autonomous channels regardless of the capability of the R/C receiver.
# Cut the PPM trace and route it thru the autopilot and back to the receiver, using the servo driver IC on your R/C receiver to drive the servos. This option requires 4 wires (Ground, PPM-in, PPM-out, Reset) and your receiver must have a supported servo driver IC. This allows you to use the large servo connectors on your R/C receiver and does not require any modification to your servos or ESC but does require you to cut a trace on your R/C receiver and limits the number of servos to the capacity of your receiver. Compatible with Classix and Tiny 1.1.
# Note that on the Classix the PPM_in pin is FOO2...

Note 1: Exact value not critical. Depending on RC Transmitter type & Manufacturer. 
Note 2: Depending on Transmitter number of Channels and t,,n,, durations. 
Note 3: Not critical. Depending on Synchro detection method.]]

<gallery>
Image:RC_Receiver_Timing_Diagram.jpg||PPM Timing Diagram
Image:RC_Receiver_Tiny.jpg|3-Wire setup, driving servos from the autopilot
Image:RC_Receiver_classix.jpg|4-Wire setup, driving servos from the R/C receiver
</gallery>
 

=== Common demux chips ===

Typical used chips are the cmos [http://www.doctronics.co.uk/4015.htm 4015] and [http://www.doctronics.co.uk/4017.htm 4017].

The 4015 uses either pin 1 or pin 9 for the clock and the input is on 7 and 15. The 4017 has just one shift register and has its clock input on pin 14 and the enable on pint 13.

In most receivers you are after the clock; though some may be pulsed; in which case you need the enable. Note that the 4017 enable has inverted logic (low to be enabled) whereas the input on the 4015 can be either (typically high). If the enable pin is held low (4017) or if the input pin (4015) is held high always;e.g. connected to the ground or the Vcc - then it is fair to assume that the PPM signal is most propably on the clock input.

== 35/40Mhz RC Receivers ==

Note that there is information on modifying other receiver models at [http://mikrokopter.de/ucwiki/RC-Empf%C3%A4nger mikrokopter.de]. It's in German however the pictures contain most of the information or use google translate.
Shielded wire is recommended for receiver and autopilot connection, as unshielded one may cause noise in receiver.

=== Futaba FP-R116FB 6 Channel FM 35MHz receiver ===

[[Image:Rc_fut_web.jpg|thumb|left|Wiring of a Futaba R136]]
*Orange wire is connected to PPM signal
*Red wire is connected to VCC
*Brown wire is connected to GND
 

=== Futaba R136F 6 Channel FM receiver ===

[[Image:rx_futaba136.jpg|thumb|left|Wiring of a Futaba R136]]
*41 MHz
*White wire is connected to PPM signal
 

=== Futaba R168DF 8 Channel dual FM receiver ===

[[Image:rx_futaba168df.jpg|thumb|left|Wiring of a Futaba R168DF]]
*35 MHz
*PPM wire is connected to 862 receiver pin on the board. VCC and GND is on the 8/B original position.
 

=== ACT Micro-6 FM receiver ===

[[Image:rx_act_micro-6.jpg|thumb|left|Wiring of a ACT Micro-6]]
*Available in 35 or 40 MHz versions
*White wire is connected to PPM signal
*[http://www.acteurope.com/Micro_6anl.pdf Datasheet (German)]
 

=== ACT DSL-4top [http://www.mikrokopter.de/ucwiki/DSL4top mikrokopter.de] version ===

[[Image:DSL4top.jpg|thumb|left|DSL-4top mikrokopter.de version]]
* Special version for mikrokopter.de - Only available in their [https://www.mikrocontroller.com/index.php?main_page=product_info&products_id=215&zenid=8ce8bab70f3e9d684e01f724316d9690 shop]!
* '''Outputs PPM directly''' on the channel 1 connector!
* No soldering necessary
* ACT Lifetime warranty
* Sells for ~45 euro
 

=== Futaba R115F 5 Channel FM receiver ===

[[Image:pprz_rx115.jpg|thumb|left|Wiring of a Futaba R115]]
*Available in 35 and 40 MHz versions
*White wire is connected to PPM signal
 

=== JETI REX 5 plus (no MPD) receiver ===

[[Image:520_Jeti_5_plus.jpg|thumb|left|Wiring of a REX 5]]

*Popular Czech made micro r/c receiver, available in 35 or 40 MHz versions
*´folded´ PCB design with parts inside, mostly inaccessable
*Small grey wire is connected to via with PPM signal
*Unusual connector used for testing, soldering recommended
*shielded wire recommended, this one taken from PC parts recycling (former soundcard to m/b connector cable)
*[http://www.jetimodel.cz/eng/navody_en/rex5_eng.pdf Datasheet (English)]
 
[[Image:DSC02414.JPG|thumb|left|other Layout of REX 5]]

=== Receiver RX-7-SYNTH IPD receiver [http://www.multiplex-rc.de/hp/produkte/artikel_detail.jsp?lfdnr=55880&action=add2notice&qty=1&cachenepper=1227896925116 Multiplex-rc.de] ===

[[Image:RX-7-SYNTH_IPD.jpg|thumb|left|Wiring of RX-7-SYNTH IPD]]

*Available in 35, 36 and 40 MHz versions
*A compact, high-quality 7-channel single-conversion FM / PPM IPD receiver
*Easy modification through connectors, see pictures
 

=== Protech 5FM 35 mHz Receiver ===

The low cost Protech '5FM' receiver makes use of an SMD version of the standard 74AHC164[http://www.ic-on-line.cn/IOL/datasheet/74ahct164_18057.pdf] 8 bit shift register; you are after PIN 1 of this chip. The circuit board has a testpad for just this pin at the top side of the circuit board.

<gallery>
Image:protech-5fm.jpg|Figure 1. Protech 5FM 35 mHZ Receiver, mark 2
Image:protech-5fm-pad.jpg|Figure 2. PPM tap location for the Protech 5FM receiver, near the 74AHC164 shift register
Image:protech-5fm-scope.jpg|Figure 3. Protech 5FM PPM signal - not very clean/digital
</gallery>

Two physical versions exist; the older one [http://www.protech.be/Manuals/PRO205manual%20web.pdf] and a newer one pictured (fig 1). It has been distributed by protech with various ready-to-fly planes; such as the Skyraider[http://www.modelbouwforum.nl/forums/beginners/50677-protech-skyraider.html].

The solder/testpad you are after the one right next the 74x164 chip its pin 1. In this image it has a jellow wire soldered to it (the yellow wire at the top left is the normal antenna connector (fig 2). Note however that the signal is not very clean (1v/div) - which may cause issues - as shown in the above image (fig 3).

This is further compunded by the relatively noisy electrical engines; which are not brushless. A ferrite coil does not seem to help enough - Papparazi and GPS loose sync often through Xbee. Replacing the engine by a brushless outrunnen resolve the issue completely.

=== Profi Penta 35 MHz ===

<gallery>
Image:DSC00547.JPG
Image:DSC00545.JPG
</gallery>

=== Graupner R16Scan ===

The Graupner R16Scan and SMC16Scan are available in 35,36,40,41Mhz versions and belongs to one of the most reliable traditional receivers in it's class. It's a highly selective PLL SCAN narrow-band FM superhet receiver. Has 8 servo connections. And the best thing; No crystals swap is required with this receiver since it scans for your TX transmission frequency. Modified for PPM output, it can output 9 separate channels.

To modify this receiver for use with an autopilot some soldering on tiny IC pins is needed. No additional electronic parts needed.

# Desolder existing resistor from IC pin, fast and carefully
# solder a short wire to the pin on the other side of the IC as on the picture, preferably als put some isolation over it
# Solder this wire to the resistor, move isolation over resistor
# Use a little UHU por glue to make sure nothing moves when flying in rought conditions

The PPM combined data is now available on connector 8. You still can power the receiver seperatly via + - pins if you want to. Or straight from the AP board 5v out.

<gallery>
Image:Graupner_R16Scan_pwm_modification_01.jpg|How to modify
Image:Graupner_R16Scan_pwm_modification_02.jpg|Modification from other side
Image:Graupner_R16Scan_pwm_modification_03.jpg|Modification Closeup
Image:Graupner_R16Scan_pwm_modification_04.jpg|Well... why not change them all in one go.
</gallery>

== 72Mhz Receivers ==

=== Castle Creations [http://www.castlecreations.com/products/berg_ms4l.html Berg 4L] ===

[[Image:berg4L.jpg|thumb|left|Wiring of a Berg 4L]]
* Expect fantastic performance from these $40 USD parts but be warned that they are known to have unreliable crystal sockets and brittle antenna wire. The ''Berg 7'' channel receiver should work equally well and is known to have a better crystal socket - note that either receiver will provide '''8 channels''' in manual R/C mode when used with Paparazzi. Note: the rugged ''Berg 4'' cannot be modified, only the ''Berg 4L'' and ''Berg 7''.

To Modify a Berg4L, follow these instructions:
# Remove the shrink wrap. Use a good knife and be careful to not damage any of the components on the receiver. I would recommend that you cut on the sides (edge of the PCB) to be sure to avoid damaging the shielding
# Desolder the headers. We will not use them with tiny AP as the servos are connected directly to the AP. This is pretty easy to do when you have a hot air rework station. If you don't have one, your best bet is to cut the header off and remove the left over pins one by one with a regular iron. There is a piece of shielding material that is connected to one of the ground pins of the header. You need to remove it carefully from the header without damaging it and re-solder it to the gnd pad.
# You need to solder 3 wires to the receiver. Gnd, +5V and PPM. To locate the PPM signal, first locate the PIC micro controller close to the location of the headers. The PPM signal is on the corner pin closest to the corner of the receiver. Soldering a 28guage wire directly to the PIN isn't very difficult. For the power connection, use the pads that were used for the header. The outside pin is Gnd, the second pin is +5V. What I did is solder the wires on the pad going straight down, then I looped the 3 wires 360 degrees and glued them to the PCB with hot glue. This provides good strain relief.
# While you have the PCB in your hands, take the opportunity to remove the crystal connector and solder your crystal directly to the PCB for added reliability.
# I also used some hot glue to add more strain relief to the antenna
# Use some large shrink wrap to cover the entire receiver again
 

=== Hitec Electron 6 72MHz Reciever ===

This was written for MNAV from crossbow but is still usable with PPRZ.

[[Image:Electron6mod.jpg|thumb|left]]
 

=== Corona Synthesized Dual-Conv Receiver 8Ch ===

[http://www.corona-rc.com/coproductshowE.asp?ArticleID=63 manual]

This receiver is available in 27,35,36,40,72 mhz and a Synthesized receiver, meaning you do not need to change frequency crystals.

How to modify for combined signal

# Cut the 8th channel PWM output pin near the PCB.
# Connected a pin from the Atmel (see picture) to the 8th channel PWM signal. (optionally, weaving the wire through some holes on the board.) Make sure you have a fine tip on your soldering iron and a magnifying glass strapped to your head!
# Glue the wire down (CA works)
# Be sure to glue the pin that you cut in place (previously, being soldered to the board was holding the pin in place)

It is maybe possible to reprogram the atmel with your own firmware. If you succeed in this plz add relevant info here.

That pin provides a 1V to 2V signal, it works with the PPRZ, although its a bit gittery (the slew rate is not real good).
<gallery>
Image:Corona_Synthesized_Receiver_72Mhz_bottom.jpg
Image:Corona_Synthesized_Receiver_72Mhz_top.jpg
Image:Corona_Synthesized_Receiver_72Mhz_top_atmel.jpg
</gallery>
 

= UHF Receivers =

Note that in most countries an amateur radio license is required to use 433MHz UHF. 
See also [[Modems#HAM_.2F_CEPT_Licence]].

== Scherrer UHF ==

[[Image:ScherrerUHF.jpg|thumb|left|Scherrer UHF Rx]]

The [http://www.webx.dk/rc/uhf-link3/uhf-link3.htm Scherrer UHF] is a high quality diversity radio control system. It has a PPM output and can be connected directely to Paparazzi. A ppm encoder board is not required. It has an RSSI output.
 

== ImmersionRC EzUHF ==

[[Image:EzUHFTx.jpg|thumb|left|ImmersionRC Tx]]

The [http://www.immersionrc.com/products.htm ImmersionRC EzUHF] is a high quality diversity radio control system. The recent firmwares have a PPM output on Ch. 1, but this needs to be activated through the PC configuration software with the proper firmware loaded. It connects directly to EzOSD and the TrackR2 which enables RSSI monitoring and head tracking for FPV.

Some people had issues with the exact timing, where the ROLL channel disappeared. If the radio has more than 6 channels, there may be methods to slave another channel to the roll channel (usually for the operation of dual ailerons). The ezuhf configuration file is using this method, where channel 1 is copied to channel 6. The EzUHF modules receive the PPM output stream from the radio and need to interpret it. For this reason, the ezuhf configuration file should be verified for proper functioning and you may find that channels are remapped to others with different purposes.

Search "sander style" antennas for a way to build your own cheap, high-quality antennas for these rx modules and which provide a range well beyond the horizon.

See [http://www.immersionrc.com/EzUHF.htm EzUHF manual+firmware] for more information.
 

[[Category:Hardware]] [[Category:User_Documentation]]

Category:Autopilots

2013-07-31T19:03:51Z

Hwarm:

__NOTOC__
__NOEDITSECTION__

{|style="border-spacing:8px;margin:0px -8px" class="MainPageBG" style="width:100%;border:1px solid #9999bf;background-color:#f5fffa;vertical-align:top;color:#000; text-align: left;"
|-valign="top"
|
<h3 style="-moz-border-radius-topright: 0.7em;
background:#cedff2;margin:-2px;padding:4px;">
[[Image:favicon32.png|32px]] Autopilots
</h3>
<div style="padding:6px;">
{{Autopilots}}
</div>

| class="MainPageBG" style="width:70%;border:1px solid #cedff2;background-color:#f5fffa;vertical-align:top"|
{|width="100%" cellpadding="2" cellspacing="5" style="vertical-align:top;background-color:#f5fffa"
|-valign="top"
| <h2 style="margin:0;background-color:#cef2e0;font-size:120%;font-weight:bold;border:1px solid #a3bfb1;text-align:left;color:#000;padding:0.2em 0.4em;">Paparazzi Autopilots</h2>
|-
|Hardware support for Autopilot versions currently in use.
|-
|[[Image:tiny13_family_top_sm.jpg|center|400px|Tiny 1.1 autopilots on the "assembly line"]]
|-
|One of the great advantages of Paparazzi is support for multiple hardware designs. The old Paparazzi board where based around ATMega MCUs. The current autopilots are designed around two primary processors:
*STM32 series microcontrollers
*LPC21xx series microcontrollers
There are active and current autopilots designs using both architectures. Not all autopilots have the same capabilities, peripherals or features, but each has advantages in different applications.

Currently, boards are designed around the STM32F1 series, but there is future upgrade path capabilities to the F2 and F4 series, giving way to feature rich processors with a variety of peripherals and speeds. Architecture-dependent firmware code is supported in part by [http://www.libopencm3.org libopencm3]. The [[Lisa]] an [[Krooz]] autopilots use the STM32.

The LPC21xx based boards use the LPC2148 and have been flying fixed wing and multi-rotors for many years. This architecture is more mature but at the expense of speed and extra ports available on the newer STM32 series processors. The [[Tiny]] series, [[Booz]], [[TWOG/v1.0 | TWOG]], [[YAPA]], [[Umarim_Lite_v2 | Umarim]] and [[NavGo_v3 | NavGo]] autopilots all use the LPC2148.

Some autopilots have also been designed for close integration with small single-board computers, particularly those based on [[OMAP]] processors such as the [http://www.gumstix.com/ Gumstix] [https://www.gumstix.com/store/index.php?cPath=33 Overo] series. The [[Lisa/L]] and [[Classix]] boards are designed with this in mind, though other autopilots can be easily interfaced. Further information can be found [[OMAP|here]].

A basic feature comparison table is presented to help in the autopilot hardware selection process. Stable tried tested LPC or more cutting edge STM32.

For information regarding architecture and firmware compatibility of various subsystems and modules, please see the appropriate [[Subsystems]] overview and [[Modules_list|Modules List]] pages.

NOTE: The accuracy of this table '''may not be 100% correct''', the best resource is always hardware and software source files and individual autopilot pages.

{| border="1" cellspacing="0" style="text-align:center" cellpadding="2%" width="100%"
|+'''Autopilot1 Feature Matrix'''
| align="center" width="12%" style="background:#f0f0f0;"|'''Feature'''
| align="center" width="11%" style="background:#f0f0f0;"|'''[[Lisa/L|Lisa/L v1.1]]'''
| align="center" width="11%" style="background:#f0f0f0;"|'''[[Lisa/M_v20|Lisa/M v2.0]]'''
| align="center" width="11%" style="background:#f0f0f0;"|'''[[KroozSD|KroozSD]]'''
| align="center" width="11%" style="background:#f0f0f0;"|'''[[Umarim_v10|Umarim v1.0]]'''
| align="center" width="11%" style="background:#f0f0f0;"|'''[[Umarim_Lite_v2|Umarim Lite v2]]'''
| align="center" width="11%" style="background:#f0f0f0;"|'''[[NavGo_v3|NavGo v3]]'''
| align="center" width="11%" style="background:#f0f0f0;"|'''[[Tiny/v2.11|Tiny v2.11]]'''
| align="center" width="11%" style="background:#f0f0f0;"|'''[[TWOG/v1.0|TWOG v1.0]]'''
| align="center" style="background:#f0f0f0;"|'''[[YAPA/v2.0|YAPA v2.0]]'''
| align="center" style="background:#f0f0f0;"|'''[[HBmini/v2.0]]'''
|-
|style="background:#f0f0f0;"| || align="center" colspan="8"|'''MCU'''
|-
| style="background:#f0f0f0;"|'''Part'''||STM32F103RE||STM32F105RCT6||STM32F405RGT6||LPC2148||LPC2148||LPC2148||LPC2148||LPC2148||LPC2148||LPC2148
|-
| style="background:#f0f0f0;"|'''Clock'''||72MHz||72MHz||168MHz||60MHz||60MHz||60MHz||60MHz||60MHz||60MHz||60MHz
|-
| style="background:#f0f0f0;"|'''Flash'''||512kB||256kB||1024kB||512kB||512kB||512kB||512kB||512kB||512kB||512kB
|-
| style="background:#f0f0f0;"|'''RAM2'''||64kB||64kB||128 & 64kB||32kB & 8kB||32kB & 8kB||32kB & 8kB||32kB & 8kB||32kB & 8kB||32kB & 8kB||32kB & 8kB
|-
|style="background:#f0f0f0;"| || align="center" colspan="8"|'''Onboard Sensors3'''
|-
| style="background:#f0f0f0;"|'''MEMS IMU'''||no||aspirin||krooz/ext||yes||yes||yes||no||no||no||yes
|-
| style="background:#f0f0f0;"|'''Magnetometer'''|| || ||yes||no||no||yes||no||no||no||yes
|-
| style="background:#f0f0f0;"|'''Barometer'''||yes||yes||yes||yes||no||yes||no||no||no||yes
|-
| style="background:#f0f0f0;"|'''Diff Pressure'''||yes||no||no||no||no||no||no||no||no||no
|-
| style="background:#f0f0f0;"|'''GPS'''||no||no||no||no||no||no||yes||no||no||no
|-
|style="background:#f0f0f0;"| || align="center" colspan="8"|'''Input/Output4'''
|-
| style="background:#f0f0f0;"|'''UART'''||3 & 1RX||2 & 2RX||3||2||2|| ||1||2||2||2
|-
| style="background:#f0f0f0;"|'''I2C'''||2||1 + 15||2||2||1||2||1||1||1||2
|-
| style="background:#f0f0f0;"|'''SPI'''||2||1||1||1||1||1||1||1||1||1
|-
| style="background:#f0f0f0;"|'''ADC'''||3 (12bit)||3 + 2 (12bit)5||4 + 1 (12bit)5||0 + 4 (10bit)||86||0 + 4 (10bit)6||0 + 1 (10bit)6||8 (10bit)||6 (10bit)||8 (10bit)(16bit)
|-
| style="background:#f0f0f0;"|'''PWM'''||6||6 + 25||10 + 15||6||6||0 + 15||8||8||10||10
|-
| style="background:#f0f0f0;"|'''PPM Output'''||no||no||no||no||no||no||1||1||no||
|-
| style="background:#f0f0f0;"|'''PPM Capture'''||1||0 + 15||1||1 + 15||1 + 15||1 + 15||1||1||1||1
|-
| style="background:#f0f0f0;"|'''GPIO7'''||?||1||2 + 15||0 + 46||0 + 46||0 + 26||2||2||1||11
|-
| style="background:#f0f0f0;"|'''Onboard LEDs'''||8||5||3||2||2||4||3||3||3||2
|-
| style="background:#f0f0f0;"|'''USB Peripheral'''||Onboard USB JTAG + UART||bootloader||bootloader||bootloader||bootloader||bootloader||bootloader||bootloader||bootloader||bootlader
|-
| style="background:#f0f0f0;"|'''CAN'''||1||1||no||no||no||no||no||no||no||
|-
| style="background:#f0f0f0;"|'''Other'''||Overo w/ I/O incl. USB Host||Aspirin footprint, JTAG header||On-board micro-USB B header, microSD slot, XBee connector|| ||On-board mini-USB B header|| || || ||XBee connector, RS232 options||JTAG,Buzzer
|-
|style="background:#f0f0f0;"| || align="center" colspan="8"|'''Power Management'''
|-
| style="background:#f0f0f0;"|'''Supply Input'''||6.1V - 18V||5V - 16V||7V - 32V||5.5V - 17V||5.5V - 17V||5.5V - 16V||6.1V - 18V||6.1V - 18V||6.1V - 18V||6.1-18V
|-
| style="background:#f0f0f0;"|'''Supply Output'''||2.25@5V, 2.25A@3.3V, Other||500mA@3.3V, 250mA@5V||1.5A@3.3V, 5A@5V||1A@3.3V, 1.5A@5V||1A@3.3V, 1.5A@5V||1A@3.3V, 1.5A@5V||1A@3.3V, 2.25A@5V||1A@3.3V, 2.25A@5V||2x 1A@3.3V, 2.25A@5V||1A@3.3V, 2.25A@5V
|-
| style="background:#f0f0f0;"|'''Software Switch'''||2||no||no||no||no||no||1||1||1||4
|-
|style="background:#f0f0f0;"| || align="center" colspan="8"|'''Mechanical'''
|-
| style="background:#f0f0f0;"|'''Size'''||~100mm x ~50mm||34mm x 60mm x 10mm||50mm x 60mm x 10mm||56mm x 25mm||53mm x 25mm||35mm x 35mm||70.8mm x 40mm||40.2mm x 30.5mm||80.0mm x 40.0mm?||57x30mm
|-
| style="background:#f0f0f0;"|'''Weight'''||?||9.9g - 10.8g||20g - 40g||9g||8g||?||24g||8g||23g w/ XBee?||30
|-
| style="background:#f0f0f0;"|'''Connector Style'''||Picoblade||Picoblade & 0.1" Servo||Picoblade & 0.1" Servo||Picoblade||Picoblade||Picoblade||Picoblade||Picoblade||0.1" Headers||Picoblade & 0.1" Servo
|-
| style="background:#f0f0f0;"|'''PCB Style'''||4-layer||4-layer||2-layer||4-layer||4-layer||4-layer||2-layer||2-layer||2-layer||4-layer
|-
| style="background:#f0f0f0;"|'''Mounting Holes'''||4x M3||4x 2mm||4x M3||4x 2mm||4x 2mm||4x 2mm||no||no||4x M3||4xM2
|-
|style="background:#f0f0f0;"| || align="center" colspan="8"|'''Comments'''
|-
| style="background:#f0f0f0;"|'''Comments'''||IMU and Overo Mount Location, Many Features|| ||High speed Cortex™-M4 168MHz processor with FPU unit, IMU, microSD card slot, OSD, onboard XBee connector||Small Dimensions, narrow fuselage form factor, IMU||Smallest Dimensions, IMU, basic version of Umarim||Small Dimensions, IMU, magnetometer & high sensitivity Barometer; designed for small rotorcraft||Onboard u-blox GPS, designed for easy DIY assembly (same as TWOG)||Basic, no onboard sensors (all external for expandability)||Specially designed to work with rs232 sensors such as XSens Mit-G/Crossbow NAV420/ig500/3DM-GX3/DMS-SGP02/MGL-sp-5. Onboard XBee connector|| can use mpu6050 or mpu6000
|-
| style="background:#f0f0f0;"|'''Typical Usage'''||Advanced payload and controls development using Gumstix; fixed-wing or rotorcraft||Small, general purpose w/ IMU; fixed-wing or rotorcraft||High integrated, high productivity board w/ IMU, microSD card, OSD and XBee; rotorcraft or fixed-wing||Small, general purpose w/ IMU; fixed-wing||Small, general purpose w/ IMU; fixed-wing||Small, general purpose w/ IMU; rotorcraft||Small, general purpose w/ GPS; fixed-wing with external IR or IMU||Small, general purpose; fixed wing with all external sensors||0.1" headers means easier wiring, at the cost of weight||For all kind of aircarft
|-
| style="background:#f0f0f0;"|'''Date Introduced'''||Summer 2010||Winter 2012||Spring 2013||Fall 2011||Summer 2012||Summer 2012||Fall 2007||Spring 2008||Spring 2011||Winter2012
|-
| style="background:#f0f0f0;"|'''Previous Versions'''||[[Lisa/L]] v1.0||[[Lisa/M_v10|Lisa/M v1.0]]||[[Krooz|Krooz]]|| || || ||[[Tiny/v1.1|Tiny v1.1]], [[Tiny/v0.99|Tiny v0.99]]|| ||[[YAPA/v1.0|YAPA v1.0]]
|}

'''Notes:'''

'''1.''' Only the newest revisions of the more commonly used autopilots are listed

'''2.''' The extra 8kB of RAM on the LPC2148 shared with the USB DMA

'''3.''' The onboard sensors are almost always supplemented with external sensors. For example, TWOG can use an external IMU or IR sensors, and also needs an external GPS.

'''4.''' Input/Outputs listed are generally those easily accessible on regular autopilot connectors, customization/hacks can modify available I/O, for example free an extra I2C on Tiny and TWOG

'''5., 6.''' Some features use shared resources - denoted by X + Y where Y is shared - and cannot be used simultaneously

'''5.''' Lisa/M v2.0 shared resources include: one I2C is shared with 2 PWM outputs, two ADCs are shared with LEDs, one RX only UART is shared with the PPM capture

'''6.''' Umarim v1.0 shared resources include: 4 ADCs are shared with 4 GPIOs

'''7.''' Usually other unused pins can be used for additional GPIO with some code modifications

|-
|<h2>Schematics, CAD files, Gerber files, BOM release strategy</h2>
|-
|<h3>About the hardware development and release process.</h3>

[https://github.com/paparazzi/paparazzi-hardware Files needed to create the hardware can be found here]. It is always good to remind oneself of the email Antoine once wrote in the mailing list before you want to start producing your own PCB's.

8 June 2011 13:25:47 Antoine Drouin wrote on the mailing list:

I've started this project together with Pascal 8 years ago and since then I have dedicated my time to try and make it successful. I'm utterly convinced of the benefits of open source, but observing how Paparazzi grew over time, I came to the conclusion that hardware is a bit different than software... "gcc tiny.brd" is not going to make a board magically appear on your desktop.

I'll list here some of my arguments in favor of releasing CAD files after the board is mature.

# Unlike software, where an unskilled user can type make and get a piece of complex software to successfully build, assembling hardware requires tools and skills. Providing gerbers and BOM have lured a bunch of new users into believing otherwise and has created tons of frustration. I've myself fixed a number of badly assembled boards and I even recall that while helping debugging a board (so after assembly), discovering that the person had manufactured two layers PCBs instead of four layers. As the technology of the autopilot increases, this problem becomes more and more important.
# The success of the project depends on the availability of affordable hardware. The price of hardware is directly and exponentially dependent on the number of manufactured units. If ten persons manufacture 10 boards each, the cost will be much higher than if one person manufactures 100.
# Last and not least, the quality of assembly also depends very much on the number of manufactured units. Good quality can only be achieved through the use of automated placing and soldering, and those processes can only be used if the number of units reach a certain amount.

|}
|}

[[Category:Hardware]] [[Category:User_Documentation]]

Sensors/IMU

2013-02-08T12:30:56Z

Hwarm: /* SparkFun Razor 6DOF IMU */

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Sensors</categorytree>
__TOC__
'''See the [[Subsystem/imu|IMU subsystem]] page for the software drivers.'''
== Terminology ==
* '''IMU''': inertial measurement unit: only measures the accelerations and rotation rates (and magnetic field)
* '''AHRS''': attitude and heading reference system: uses IMU data + extra (airspeed/GPS/baro/...) to do sensor fusion and provide pitch and roll
* '''INS''': integrated navigation system: uses IMU + Navigation sensor(s) (e.g. GPS) + even more complex algorithms that besides pitch and roll also interpolates positions and velocities using the attitude corrected acceleration measurements.

== Paparazzi IMUs ==

=== Booz IMU v 1.01 ===

*High quality analog devices sensors
*16bit ADC capable of 200 000 samples per second
*Special attention to clean power with onboard linear supplies
*Efficient high-speed SPI for minimal microcontroller overhead and ultra-low latency (=better controller performance).
*Fits on Booz, Lisa AND Tiny/TWOG autopilots.

While originally designed for use with rotorcrafts, code is now available for use with fixed wing.

[[Image:IMU001.jpg|240px]]

The hardware description is [[BoozIMU|here]].

Available at [https://mini.ppzuav.com/osc/product_info.php?cPath=15&products_id=122&osCsid=bq9cget2u5c7ksa6kd9ssdf03lisuksq PPZUAV].

=== YAI v1.0 ===

Why "yet another imu" while there are already so many out there?

[[Image:yai_assemb.jpg|240px]]

*Designed to be completely compatible with original booz IMU and its code
*Cheaper sensors (lower bias stability)
*Higher resolution (16bits) and frequency (200ksps) and cleaner onboard power supply, better grounding and shielding than compared with e.g. external sparkfun breakout boards
*Fast low latency SPI communication (no uart as the tiny/twog miss uarts)
*The most important part of attitude determination is proper kinematic compensation using for instance GPS, pressure sensors etc etc. When using IMU with external processors there is often less flexibility. Things as timing for instance are as important as the quality of the gyros themselves.

Board, BOM -> [ http://svn.savannah.nongnu.org/viewvc/paparazzi-hardware/trunk/sensors/yai/?root=paparazzi Hardware Repository]

=== Aspirin IMU ===

[[Image:Aspirin_imu_front.jpg|240px]]

[[AspirinIMU|Next generation flat imu.]] This little imu with latest generation of integrated high rate high resolution gyros's moreover has very low noise and stable power supplies and outputs all sensors interrupt pins for optimal performance.

Note: while the main intended use is the very low latency high performance spi+i2c+interrupts connection (e.g. on lisa/M), please note that aspirin v2 can also be used with any tiny/twog for fixedwing aircraft with the same 4-wire interface and identical software as the PPZUAV-IMU. (connect Aspirin-SCK and aspirin-SCL to the I2C-SCL, aspirin-mosi and aspirin-SDA to I2C-SDA, Vcc to 5V (preferably linear), aspirin-gnd and aspirin-miso to GND, and aspirin-CS to 3.3V.)

Detailed information about the [[AspirinIMU|Aspirin IMU]] is available [[AspirinIMU|here.]]

== 3rd Party IMU ==

'''Loose Terminology Note:''' Like the sparkfun website, the following text incorrectly equates the term "degree-of-freedom" with sensor measurement. Unless we're talking about articulated arms (which paparazzi to date isn't involved with), a body can only have 6 physical DOFs and that would correspond to translation and rotations in the x,y,z cartesian directions of 3D space. If the vehicle state vector includes positions and velocities for each degree of freedom, the state vector would have a dimension of 6 x 2 = 12 states. The goal is to reconstruct these vehicle states using sensor measurements, as once the states can be obtained with reasonable certainty, a control algorithm can have a shot at controlling the system. Using various filtering techniques, multiple sensor types can be combined to estimate these states.

IMU's measure rotation rates, acceleration (6DOF) and some also magnetic fields (9DOF). This data is used by an autopilot to estimate the state of the aircraft. They that can be used with a Paparazzi autopilot based UAS. If you happen to have such a device, we really would love to see that you share your IMU paparazzi autopilot integration projects information on this Wiki.

=== PPZUAV IMU 9DOF ===
<gallery>
Image:Ppz9dofimu.jpg|9DOM IMU
Image:Ppz9dofimumed.jpg|Example Wiring to Tiny2.11
Image:Ppz9domschematic.jpg|Schematic
</gallery>


Another IMU based around the ITG-3200, ADXL345 and HMC5843. 
Features: I2C out 5v input. Interrupts . 
PCBs available from PPZUAV (assemblies soon). Schematic open, design is Altium Designer, gerbers available. 


A sample airframe illustrating all calibration issues and reading and merging the sensor at 100Hz with minimal control delays is in the repository to get you started:

airframe: PPZUAV/fixedwing/tiny_imu.xml
settings: tuning_basic_ins.xml
telemetry: default_fixedwing_imu.xml

Credit and thanks go out to Christophe for making the code and testing.

Media
YouTube: http://www.youtube.com/watch?v=OaMTyJ-s-PU
 

=== Ryan Mechatronics CHIMU AHRS ===

Very nice product: using the ultra high speed ultra low latency 200Hz SPI-slave mode (even 200Hz innerloop control of fixedwing is possible) or simple 4-wire connection via serial port to any TWOG/TINY/LISA/YAPA.

Don't want to spend time testing AHRS filters? Nor calibrating IMU? This module with molex connector can be bought calibrated and does all the filtering internally.

Use it with highspeed SPI on LPC-based boards: http://www.youtube.com/watch?v=mxx-f3Ur0L8

<modules>
<load name="ins_chimu_spi.xml" />
</modules>

...

<subsystem name="spi_slave_hs"/>

Use CHIMU with simple uart connection on both lisa or tiny/twog

<modules>
<load name="ins_chimu_uart.xml">
<configure name="CHIMU_UART_NR" value="0"/>
</load>
</modules>

=== SparkFun Razor 6DOF IMU ===

[[Image:RazzorIMU.jpg|thumb|left|Razor IMU (top) with the tiny13 autopilot]]

[[Image:RazzorIMUb.jpg|thumb|left|Razor IMU in the tiny13 autopilot box]]

[http://www.sparkfun.com/commerce/product_info.php?products_id=10010 Official website]

6DOF - Ultra-Thin IMU

Very cheap, currently 62-72 Euro. [http://www.watterott.com/de/Sensoren/IMU Shop in Europe]

Has been integrated in Paparazzi by implementing the DCM algorihm from William Premerlani and Paul Bizard by Hochschule Bremen, Germany.

Remove the high pass filters of the RazorIMU to get better results.

For the Twog and Tiny 2.2 autopilots you have also remove the resistors to GND and the series resistors to the MC of the 5V analog inputs. The code to fly normal plane is currently in the repository. Christoph is working on improvements look here: http://paparazzi.enac.fr/wiki/User:Christoph

[[Media:Wiring_Razor_IMU.pdf|Connections and wiring to the tiny13]]

 

=== Drotek MPU6050 ===

[[Image:drotek1.jpg|thumb|left|component side]]
[[Image:drotek2.jpg|thumb|left|solder side]]

IMU Drotek MPU6050 - 6 Degrees of Freedom Invensens MPU6050

http://www.drotek.fr/shop/en/42-mpu6050-gyro-accelerometer.html

Tiny, very low cost < 13 Euro , 5V and 3.3V input, I2C interface.

This IMU has been tested for TWOG, Tiny 1.3, HBmini, Umarin, YAPA and flown with YAPA.
Note that this sensor use the alternative I2C address. Correct is in the driver file. It is a low cost and precise solution for normal aircraft.

 

=== Drotek MPU6050-hmc5883-ms5611 ===

[[Image:drotek3.jpg|thumb|left|component side]]
[[Image:drotek4.jpg|thumb|left|solder side]]

IMU Drotek MPU6050 - 10 Degrees of Freedom

http://www.drotek.fr/shop/en/62-imu-10dof-mpu6050-hmc5883-ms5611.html

Tiny, low cost < 36 Euro , 5V and 3.3V input, I2C interface.

Note that the MPU6050 sensor use the alternative I2C address and that the hmc5883 ms5611 are connected
to the autopilot I2C bus. Correct the address in the driver file of the MPU6050. Use the separate HMC5883 and ms5611 sensor drivers.
It is a low cost and precise solution for normal aircraft with a excellent baro sensor.

 

=== SparkFun SEN-10121 ===
[[Image:SEN-10121.jpg|thumb|left|SEN-10121]]

IMU Digital Combo Board - 6 Degrees of Freedom ITG3200/ADXL345

http://www.sparkfun.com/products/10121

Tiny, ADXL345 accelerometer, ITG-3200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with Tiny v2.11 and TWOG. It is very similar to the PPZUAV IMU.

Details of [[IMU/SEN-10121|configuration]].

 

=== Pololu MinIMU-9 ===
[[Image:MinIMU9.jpg|thumb|left|MinIMU-9]]

IMU Digital Combo Board - 9 Degrees of Freedom L3G4200/LSM303

http://www.pololu.com/catalog/product/1265

Tiny, LSM303 accelerometer and magnetometer, L3G4200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with TWOG.

Details of [[IMU/MinIMU-9|configuration]].

 

=== Cloudcap Crista IMU ===
[[Image:crista_sensorhead.jpg|thumb|left|Christa IMU]]

[http://www.cloudcaptech.com/crista_sensorhead.shtm Official website]

More infos soon.

 

== 3rd Party INS ==

INS measure rates with their sensors and run algorithms to estimate the state on their own. They give this information the the autopilot (e.g. Euler angles) that can then use it for navigation.

===[http://diydrones.com/profiles/blogs/arduimu-v2-flat-now-available|DIYDrones ArduIMU+ V2 (Flat)] ===
[[Image:ArduIMU.jpg|thumb|left|ArduIMU]]

[http://code.google.com/p/ardu-imu/wiki/HomePage?tm=6 Official website]

[[ArduIMU|Paparazzi Wiki Page]]

* 3 axis accelerometer + 3 axis gyroscope
* Low cost
* Has been integrated in Paparazzi by ZHAW, Winterthur, Switzerland.
* A magnetometer has been integrated in the software to compensate drift in yaw.
* GPS data from the Tiny is passed over I2C to the AHRS on the IMU.
* Is sold by [http://www.sparkfun.com/products/9956 Sparkfun] and [http://store.diydrones.com/ProductDetails.asp?ProductCode=KT-ArduIMU-20 DIYDrones Store].
 

=== Vector-Nav VN-100 ===
[[Image:VN-100.jpg|thumb|left|Vector-Nav VN-100]]

[http://www.vectornav.com/vn-100-features Official website]

There is a [[Modules|module]] for this AHRS (ins_vn100.xml for fixedwings).

 

=== MicroStrain 3DM-GX2 ===
[[Image:3DM-GX2.jpg|thumb|left|MicroStrain 3DM-GX2]]

[http://www.microstrain.com/3dm-gx2.aspx Official website]

More info soon.

 

=== Xsens MTi and MTi-G (with GPS) ===
[[Image:MTi.jpeg|thumb|left|Xsens MTi]]

[[Image:MTi-G.jpeg|thumb|left|Xsens MTi-G (with GPS)]]

[http://www.xsens.com/en/general/mti Official website MTi]

[http://www.xsens.com/en/general/mti-g Official website MTi-G]

In sensor fusion, calibration and timing are crucial. If you want latency compensated ADXRS gyro integrated attitude done by an efficient and optimized Blackfin DSP you need an XSens. For rotorcraft the 100Hz is a bit slow, but for fixedwing it's perfect. Directly compatible with [[Yapa]] and [[Lisa]] and all needed code in paparazi.

 

=== MemSense MAG3 ===

MAG3 - 6 DOF Analog IMU with Triaxial Magnetometer

[http://www.memsense.com/index.php/Product-Pages/mag3-worlds-smallest-analog-inertial-measurement-unit.html Official website mag3]

== The Very Short Essential Introduction To Inertial Attitude Estimation ==

The only physical entity related to attitude (pitch and roll) is the earth gravity vector (unless you use a multi-antenna phase-measuring GPS... $$$$). Unfortunately, the sensors that measure gravity (=accelerometers) also measure so-called kinematic accelerations or in other words: changes in speed: like centrifugal forces, Coriolis forces, linear accelerations etc... The sum of all these litteraly is "what you feel" and is called [http://en.wikipedia.org/wiki/Specific_force "specific force"].

so

accelerometer_value (specific force) = earth_gravity + change in velocity (linear accelerations) + velocity times turn rate (centrifugal etc)

or

A = B + C + D

You measure A and want to know B. What all "gyroscopes and accelerometer only" AHRS projects are doing in some way or another is to neglect the last 2 (C and D). In many situations this is not bad: for instance: when testing the AHRS attached to your computer: it can not accelerate for a very long time (at most a few meters: so if you accerate to the left, then you need to accelerate to the right directly after so the average is zero) and can not rotate to much either (or your cable gets strangled). This is why all AHRS videos on youtube look perfect. And on the desk they are perfect: you neglected 2 terms in the equation that in that situation are perfectly neglect-able. Also with a quadrotor that hovers and keeps its nose in the same direction all the time, these neglected terms are small.

Now what about the gyroscopes you might ask. I deliberately keep them only second as gyroscopes (turn rate or rotation speed sensors) do NOT give you attitude but ONLY HELP TO SOLVE SHORT TERM errors in the previous part. If gyroscopes would measure turn-rate perfectly, then they would help more but all MEMS/PIEZZO sensors are more or less sensitive to 1) temperature, 2) turnrate, 3) vibrations, 4) accelerations, 5) radiation, 6) power supply quality 7) non-linearity 8) ADC-quality 9) dynamic range and saturation problems, ... so if you integrate gyroscopes, sooner or later errors build up (drift). I put this list here so you know what to pay attention for: if using gyroscopes: always try to keep the temperature as constant as possible or let the temperature settle, reduce vibrations (dampers), use better ADC (e.g. 10bit ADC with +/- 1200 deg/sec gyros have a resolution of 2.4 degrees/s per ADC tick, so your phi/theta might drift 1.2deg/sec without noticing) and power supply filtering and shielding etc to start with. All of these define for how long (seconds!/minutes?) gyroscope integration is useful.

If you convert the accelerometer directly to attitude and plot it, it will vibrate a lot and will show errors when you accelerate the AHRS on your desk. During a coordinated turn of a fixedwing plane, the force you feel is perpendicular to the plane (not pointing to earth). The accelerometer only clearly is insufficient to know your attitude. One solution is to use gyroscopes that are so good that you can predict for many minutes (then the average acceleration during several turns would still point to earth). But if your gyros can only help for shorter terms (like all MEMS sensors of less than 500euro/each) then extra information is required. E.g: if you add GPS data or airspeed data however, from the flightpath you can quite accurately reconstruct the missing C and D terms. Together with the accelerometer you can know "where the earth is" even when you keep accelerating and turning. Here questions like latency, update rate, noisy derivatives (linear acceleration) are of importance.

Finally there is the heading... GPS ground-track is not the same as nose direction. Gyroscopes measure how much the nose has been turning, so using GPS to correct it induces errors that increase with corsswind. Magnetometers can help here, and become necessary whenever you do not move enough anymore (hovering). This situation can also occur in plane flying in very strong winds.

See the [[Subsystem/ahrs|AHRS subsystem]] page for an overview of some algorithm implementations.

[[Category:Sensors]]

Sensors/IMU

2013-02-08T12:29:19Z

Hwarm: /* SparkFun Razor 6DOF IMU */

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Sensors</categorytree>
__TOC__
'''See the [[Subsystem/imu|IMU subsystem]] page for the software drivers.'''
== Terminology ==
* '''IMU''': inertial measurement unit: only measures the accelerations and rotation rates (and magnetic field)
* '''AHRS''': attitude and heading reference system: uses IMU data + extra (airspeed/GPS/baro/...) to do sensor fusion and provide pitch and roll
* '''INS''': integrated navigation system: uses IMU + Navigation sensor(s) (e.g. GPS) + even more complex algorithms that besides pitch and roll also interpolates positions and velocities using the attitude corrected acceleration measurements.

== Paparazzi IMUs ==

=== Booz IMU v 1.01 ===

*High quality analog devices sensors
*16bit ADC capable of 200 000 samples per second
*Special attention to clean power with onboard linear supplies
*Efficient high-speed SPI for minimal microcontroller overhead and ultra-low latency (=better controller performance).
*Fits on Booz, Lisa AND Tiny/TWOG autopilots.

While originally designed for use with rotorcrafts, code is now available for use with fixed wing.

[[Image:IMU001.jpg|240px]]

The hardware description is [[BoozIMU|here]].

Available at [https://mini.ppzuav.com/osc/product_info.php?cPath=15&products_id=122&osCsid=bq9cget2u5c7ksa6kd9ssdf03lisuksq PPZUAV].

=== YAI v1.0 ===

Why "yet another imu" while there are already so many out there?

[[Image:yai_assemb.jpg|240px]]

*Designed to be completely compatible with original booz IMU and its code
*Cheaper sensors (lower bias stability)
*Higher resolution (16bits) and frequency (200ksps) and cleaner onboard power supply, better grounding and shielding than compared with e.g. external sparkfun breakout boards
*Fast low latency SPI communication (no uart as the tiny/twog miss uarts)
*The most important part of attitude determination is proper kinematic compensation using for instance GPS, pressure sensors etc etc. When using IMU with external processors there is often less flexibility. Things as timing for instance are as important as the quality of the gyros themselves.

Board, BOM -> [ http://svn.savannah.nongnu.org/viewvc/paparazzi-hardware/trunk/sensors/yai/?root=paparazzi Hardware Repository]

=== Aspirin IMU ===

[[Image:Aspirin_imu_front.jpg|240px]]

[[AspirinIMU|Next generation flat imu.]] This little imu with latest generation of integrated high rate high resolution gyros's moreover has very low noise and stable power supplies and outputs all sensors interrupt pins for optimal performance.

Note: while the main intended use is the very low latency high performance spi+i2c+interrupts connection (e.g. on lisa/M), please note that aspirin v2 can also be used with any tiny/twog for fixedwing aircraft with the same 4-wire interface and identical software as the PPZUAV-IMU. (connect Aspirin-SCK and aspirin-SCL to the I2C-SCL, aspirin-mosi and aspirin-SDA to I2C-SDA, Vcc to 5V (preferably linear), aspirin-gnd and aspirin-miso to GND, and aspirin-CS to 3.3V.)

Detailed information about the [[AspirinIMU|Aspirin IMU]] is available [[AspirinIMU|here.]]

== 3rd Party IMU ==

'''Loose Terminology Note:''' Like the sparkfun website, the following text incorrectly equates the term "degree-of-freedom" with sensor measurement. Unless we're talking about articulated arms (which paparazzi to date isn't involved with), a body can only have 6 physical DOFs and that would correspond to translation and rotations in the x,y,z cartesian directions of 3D space. If the vehicle state vector includes positions and velocities for each degree of freedom, the state vector would have a dimension of 6 x 2 = 12 states. The goal is to reconstruct these vehicle states using sensor measurements, as once the states can be obtained with reasonable certainty, a control algorithm can have a shot at controlling the system. Using various filtering techniques, multiple sensor types can be combined to estimate these states.

IMU's measure rotation rates, acceleration (6DOF) and some also magnetic fields (9DOF). This data is used by an autopilot to estimate the state of the aircraft. They that can be used with a Paparazzi autopilot based UAS. If you happen to have such a device, we really would love to see that you share your IMU paparazzi autopilot integration projects information on this Wiki.

=== PPZUAV IMU 9DOF ===
<gallery>
Image:Ppz9dofimu.jpg|9DOM IMU
Image:Ppz9dofimumed.jpg|Example Wiring to Tiny2.11
Image:Ppz9domschematic.jpg|Schematic
</gallery>


Another IMU based around the ITG-3200, ADXL345 and HMC5843. 
Features: I2C out 5v input. Interrupts . 
PCBs available from PPZUAV (assemblies soon). Schematic open, design is Altium Designer, gerbers available. 


A sample airframe illustrating all calibration issues and reading and merging the sensor at 100Hz with minimal control delays is in the repository to get you started:

airframe: PPZUAV/fixedwing/tiny_imu.xml
settings: tuning_basic_ins.xml
telemetry: default_fixedwing_imu.xml

Credit and thanks go out to Christophe for making the code and testing.

Media
YouTube: http://www.youtube.com/watch?v=OaMTyJ-s-PU
 

=== Ryan Mechatronics CHIMU AHRS ===

Very nice product: using the ultra high speed ultra low latency 200Hz SPI-slave mode (even 200Hz innerloop control of fixedwing is possible) or simple 4-wire connection via serial port to any TWOG/TINY/LISA/YAPA.

Don't want to spend time testing AHRS filters? Nor calibrating IMU? This module with molex connector can be bought calibrated and does all the filtering internally.

Use it with highspeed SPI on LPC-based boards: http://www.youtube.com/watch?v=mxx-f3Ur0L8

<modules>
<load name="ins_chimu_spi.xml" />
</modules>

...

<subsystem name="spi_slave_hs"/>

Use CHIMU with simple uart connection on both lisa or tiny/twog

<modules>
<load name="ins_chimu_uart.xml">
<configure name="CHIMU_UART_NR" value="0"/>
</load>
</modules>

=== SparkFun Razor 6DOF IMU ===

[[Image:RazzorIMU.jpg|thumb|left|Razor IMU (top) with the tiny13 autopilot]]

[[Image:RazzorIMUb.jpg|thumb|left|Razor IMU in the tiny13 autopilot box]]

[http://www.sparkfun.com/commerce/product_info.php?products_id=10010 Official website]

6DOF - Ultra-Thin IMU

Very cheap, currently 62-72 Euro. [http://www.watterott.com/de/Sensoren/IMU Shop in Europe]

Has been integrated in Paparazzi by implementing the DCM algorihm by Hochschule Bremen, Germany.

Remove the high pass filters of the RazorIMU to get better results.

For the Twog and Tiny 2.2 autopilots you have also remove the resistors to GND and the series resistors to the MC of the 5V analog inputs. The code to fly normal plane is currently in the repository. Christoph is working on improvements look here: http://paparazzi.enac.fr/wiki/User:Christoph

[[Media:Wiring_Razor_IMU.pdf|Connections and wiring to the tiny13]]

 

=== Drotek MPU6050 ===

[[Image:drotek1.jpg|thumb|left|component side]]
[[Image:drotek2.jpg|thumb|left|solder side]]

IMU Drotek MPU6050 - 6 Degrees of Freedom Invensens MPU6050

http://www.drotek.fr/shop/en/42-mpu6050-gyro-accelerometer.html

Tiny, very low cost < 13 Euro , 5V and 3.3V input, I2C interface.

This IMU has been tested for TWOG, Tiny 1.3, HBmini, Umarin, YAPA and flown with YAPA.
Note that this sensor use the alternative I2C address. Correct is in the driver file. It is a low cost and precise solution for normal aircraft.

 

=== Drotek MPU6050-hmc5883-ms5611 ===

[[Image:drotek3.jpg|thumb|left|component side]]
[[Image:drotek4.jpg|thumb|left|solder side]]

IMU Drotek MPU6050 - 10 Degrees of Freedom

http://www.drotek.fr/shop/en/62-imu-10dof-mpu6050-hmc5883-ms5611.html

Tiny, low cost < 36 Euro , 5V and 3.3V input, I2C interface.

Note that the MPU6050 sensor use the alternative I2C address and that the hmc5883 ms5611 are connected
to the autopilot I2C bus. Correct the address in the driver file of the MPU6050. Use the separate HMC5883 and ms5611 sensor drivers.
It is a low cost and precise solution for normal aircraft with a excellent baro sensor.

 

=== SparkFun SEN-10121 ===
[[Image:SEN-10121.jpg|thumb|left|SEN-10121]]

IMU Digital Combo Board - 6 Degrees of Freedom ITG3200/ADXL345

http://www.sparkfun.com/products/10121

Tiny, ADXL345 accelerometer, ITG-3200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with Tiny v2.11 and TWOG. It is very similar to the PPZUAV IMU.

Details of [[IMU/SEN-10121|configuration]].

 

=== Pololu MinIMU-9 ===
[[Image:MinIMU9.jpg|thumb|left|MinIMU-9]]

IMU Digital Combo Board - 9 Degrees of Freedom L3G4200/LSM303

http://www.pololu.com/catalog/product/1265

Tiny, LSM303 accelerometer and magnetometer, L3G4200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with TWOG.

Details of [[IMU/MinIMU-9|configuration]].

 

=== Cloudcap Crista IMU ===
[[Image:crista_sensorhead.jpg|thumb|left|Christa IMU]]

[http://www.cloudcaptech.com/crista_sensorhead.shtm Official website]

More infos soon.

 

== 3rd Party INS ==

INS measure rates with their sensors and run algorithms to estimate the state on their own. They give this information the the autopilot (e.g. Euler angles) that can then use it for navigation.

===[http://diydrones.com/profiles/blogs/arduimu-v2-flat-now-available|DIYDrones ArduIMU+ V2 (Flat)] ===
[[Image:ArduIMU.jpg|thumb|left|ArduIMU]]

[http://code.google.com/p/ardu-imu/wiki/HomePage?tm=6 Official website]

[[ArduIMU|Paparazzi Wiki Page]]

* 3 axis accelerometer + 3 axis gyroscope
* Low cost
* Has been integrated in Paparazzi by ZHAW, Winterthur, Switzerland.
* A magnetometer has been integrated in the software to compensate drift in yaw.
* GPS data from the Tiny is passed over I2C to the AHRS on the IMU.
* Is sold by [http://www.sparkfun.com/products/9956 Sparkfun] and [http://store.diydrones.com/ProductDetails.asp?ProductCode=KT-ArduIMU-20 DIYDrones Store].
 

=== Vector-Nav VN-100 ===
[[Image:VN-100.jpg|thumb|left|Vector-Nav VN-100]]

[http://www.vectornav.com/vn-100-features Official website]

There is a [[Modules|module]] for this AHRS (ins_vn100.xml for fixedwings).

 

=== MicroStrain 3DM-GX2 ===
[[Image:3DM-GX2.jpg|thumb|left|MicroStrain 3DM-GX2]]

[http://www.microstrain.com/3dm-gx2.aspx Official website]

More info soon.

 

=== Xsens MTi and MTi-G (with GPS) ===
[[Image:MTi.jpeg|thumb|left|Xsens MTi]]

[[Image:MTi-G.jpeg|thumb|left|Xsens MTi-G (with GPS)]]

[http://www.xsens.com/en/general/mti Official website MTi]

[http://www.xsens.com/en/general/mti-g Official website MTi-G]

In sensor fusion, calibration and timing are crucial. If you want latency compensated ADXRS gyro integrated attitude done by an efficient and optimized Blackfin DSP you need an XSens. For rotorcraft the 100Hz is a bit slow, but for fixedwing it's perfect. Directly compatible with [[Yapa]] and [[Lisa]] and all needed code in paparazi.

 

=== MemSense MAG3 ===

MAG3 - 6 DOF Analog IMU with Triaxial Magnetometer

[http://www.memsense.com/index.php/Product-Pages/mag3-worlds-smallest-analog-inertial-measurement-unit.html Official website mag3]

== The Very Short Essential Introduction To Inertial Attitude Estimation ==

The only physical entity related to attitude (pitch and roll) is the earth gravity vector (unless you use a multi-antenna phase-measuring GPS... $$$$). Unfortunately, the sensors that measure gravity (=accelerometers) also measure so-called kinematic accelerations or in other words: changes in speed: like centrifugal forces, Coriolis forces, linear accelerations etc... The sum of all these litteraly is "what you feel" and is called [http://en.wikipedia.org/wiki/Specific_force "specific force"].

so

accelerometer_value (specific force) = earth_gravity + change in velocity (linear accelerations) + velocity times turn rate (centrifugal etc)

or

A = B + C + D

You measure A and want to know B. What all "gyroscopes and accelerometer only" AHRS projects are doing in some way or another is to neglect the last 2 (C and D). In many situations this is not bad: for instance: when testing the AHRS attached to your computer: it can not accelerate for a very long time (at most a few meters: so if you accerate to the left, then you need to accelerate to the right directly after so the average is zero) and can not rotate to much either (or your cable gets strangled). This is why all AHRS videos on youtube look perfect. And on the desk they are perfect: you neglected 2 terms in the equation that in that situation are perfectly neglect-able. Also with a quadrotor that hovers and keeps its nose in the same direction all the time, these neglected terms are small.

Now what about the gyroscopes you might ask. I deliberately keep them only second as gyroscopes (turn rate or rotation speed sensors) do NOT give you attitude but ONLY HELP TO SOLVE SHORT TERM errors in the previous part. If gyroscopes would measure turn-rate perfectly, then they would help more but all MEMS/PIEZZO sensors are more or less sensitive to 1) temperature, 2) turnrate, 3) vibrations, 4) accelerations, 5) radiation, 6) power supply quality 7) non-linearity 8) ADC-quality 9) dynamic range and saturation problems, ... so if you integrate gyroscopes, sooner or later errors build up (drift). I put this list here so you know what to pay attention for: if using gyroscopes: always try to keep the temperature as constant as possible or let the temperature settle, reduce vibrations (dampers), use better ADC (e.g. 10bit ADC with +/- 1200 deg/sec gyros have a resolution of 2.4 degrees/s per ADC tick, so your phi/theta might drift 1.2deg/sec without noticing) and power supply filtering and shielding etc to start with. All of these define for how long (seconds!/minutes?) gyroscope integration is useful.

If you convert the accelerometer directly to attitude and plot it, it will vibrate a lot and will show errors when you accelerate the AHRS on your desk. During a coordinated turn of a fixedwing plane, the force you feel is perpendicular to the plane (not pointing to earth). The accelerometer only clearly is insufficient to know your attitude. One solution is to use gyroscopes that are so good that you can predict for many minutes (then the average acceleration during several turns would still point to earth). But if your gyros can only help for shorter terms (like all MEMS sensors of less than 500euro/each) then extra information is required. E.g: if you add GPS data or airspeed data however, from the flightpath you can quite accurately reconstruct the missing C and D terms. Together with the accelerometer you can know "where the earth is" even when you keep accelerating and turning. Here questions like latency, update rate, noisy derivatives (linear acceleration) are of importance.

Finally there is the heading... GPS ground-track is not the same as nose direction. Gyroscopes measure how much the nose has been turning, so using GPS to correct it induces errors that increase with corsswind. Magnetometers can help here, and become necessary whenever you do not move enough anymore (hovering). This situation can also occur in plane flying in very strong winds.

See the [[Subsystem/ahrs|AHRS subsystem]] page for an overview of some algorithm implementations.

[[Category:Sensors]]

File:Drotek4.jpg

2013-02-08T12:19:16Z

Hwarm:

File:Drotek3.jpg

2013-02-08T12:18:36Z

Hwarm:

Sensors/IMU

2013-02-08T12:12:05Z

Hwarm: /* 3rd Party IMU */

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Sensors</categorytree>
__TOC__
'''See the [[Subsystem/imu|IMU subsystem]] page for the software drivers.'''
== Terminology ==
* '''IMU''': inertial measurement unit: only measures the accelerations and rotation rates (and magnetic field)
* '''AHRS''': attitude and heading reference system: uses IMU data + extra (airspeed/GPS/baro/...) to do sensor fusion and provide pitch and roll
* '''INS''': integrated navigation system: uses IMU + Navigation sensor(s) (e.g. GPS) + even more complex algorithms that besides pitch and roll also interpolates positions and velocities using the attitude corrected acceleration measurements.

== Paparazzi IMUs ==

=== Booz IMU v 1.01 ===

*High quality analog devices sensors
*16bit ADC capable of 200 000 samples per second
*Special attention to clean power with onboard linear supplies
*Efficient high-speed SPI for minimal microcontroller overhead and ultra-low latency (=better controller performance).
*Fits on Booz, Lisa AND Tiny/TWOG autopilots.

While originally designed for use with rotorcrafts, code is now available for use with fixed wing.

[[Image:IMU001.jpg|240px]]

The hardware description is [[BoozIMU|here]].

Available at [https://mini.ppzuav.com/osc/product_info.php?cPath=15&products_id=122&osCsid=bq9cget2u5c7ksa6kd9ssdf03lisuksq PPZUAV].

=== YAI v1.0 ===

Why "yet another imu" while there are already so many out there?

[[Image:yai_assemb.jpg|240px]]

*Designed to be completely compatible with original booz IMU and its code
*Cheaper sensors (lower bias stability)
*Higher resolution (16bits) and frequency (200ksps) and cleaner onboard power supply, better grounding and shielding than compared with e.g. external sparkfun breakout boards
*Fast low latency SPI communication (no uart as the tiny/twog miss uarts)
*The most important part of attitude determination is proper kinematic compensation using for instance GPS, pressure sensors etc etc. When using IMU with external processors there is often less flexibility. Things as timing for instance are as important as the quality of the gyros themselves.

Board, BOM -> [ http://svn.savannah.nongnu.org/viewvc/paparazzi-hardware/trunk/sensors/yai/?root=paparazzi Hardware Repository]

=== Aspirin IMU ===

[[Image:Aspirin_imu_front.jpg|240px]]

[[AspirinIMU|Next generation flat imu.]] This little imu with latest generation of integrated high rate high resolution gyros's moreover has very low noise and stable power supplies and outputs all sensors interrupt pins for optimal performance.

Note: while the main intended use is the very low latency high performance spi+i2c+interrupts connection (e.g. on lisa/M), please note that aspirin v2 can also be used with any tiny/twog for fixedwing aircraft with the same 4-wire interface and identical software as the PPZUAV-IMU. (connect Aspirin-SCK and aspirin-SCL to the I2C-SCL, aspirin-mosi and aspirin-SDA to I2C-SDA, Vcc to 5V (preferably linear), aspirin-gnd and aspirin-miso to GND, and aspirin-CS to 3.3V.)

Detailed information about the [[AspirinIMU|Aspirin IMU]] is available [[AspirinIMU|here.]]

== 3rd Party IMU ==

'''Loose Terminology Note:''' Like the sparkfun website, the following text incorrectly equates the term "degree-of-freedom" with sensor measurement. Unless we're talking about articulated arms (which paparazzi to date isn't involved with), a body can only have 6 physical DOFs and that would correspond to translation and rotations in the x,y,z cartesian directions of 3D space. If the vehicle state vector includes positions and velocities for each degree of freedom, the state vector would have a dimension of 6 x 2 = 12 states. The goal is to reconstruct these vehicle states using sensor measurements, as once the states can be obtained with reasonable certainty, a control algorithm can have a shot at controlling the system. Using various filtering techniques, multiple sensor types can be combined to estimate these states.

IMU's measure rotation rates, acceleration (6DOF) and some also magnetic fields (9DOF). This data is used by an autopilot to estimate the state of the aircraft. They that can be used with a Paparazzi autopilot based UAS. If you happen to have such a device, we really would love to see that you share your IMU paparazzi autopilot integration projects information on this Wiki.

=== PPZUAV IMU 9DOF ===
<gallery>
Image:Ppz9dofimu.jpg|9DOM IMU
Image:Ppz9dofimumed.jpg|Example Wiring to Tiny2.11
Image:Ppz9domschematic.jpg|Schematic
</gallery>


Another IMU based around the ITG-3200, ADXL345 and HMC5843. 
Features: I2C out 5v input. Interrupts . 
PCBs available from PPZUAV (assemblies soon). Schematic open, design is Altium Designer, gerbers available. 


A sample airframe illustrating all calibration issues and reading and merging the sensor at 100Hz with minimal control delays is in the repository to get you started:

airframe: PPZUAV/fixedwing/tiny_imu.xml
settings: tuning_basic_ins.xml
telemetry: default_fixedwing_imu.xml

Credit and thanks go out to Christophe for making the code and testing.

Media
YouTube: http://www.youtube.com/watch?v=OaMTyJ-s-PU
 

=== Ryan Mechatronics CHIMU AHRS ===

Very nice product: using the ultra high speed ultra low latency 200Hz SPI-slave mode (even 200Hz innerloop control of fixedwing is possible) or simple 4-wire connection via serial port to any TWOG/TINY/LISA/YAPA.

Don't want to spend time testing AHRS filters? Nor calibrating IMU? This module with molex connector can be bought calibrated and does all the filtering internally.

Use it with highspeed SPI on LPC-based boards: http://www.youtube.com/watch?v=mxx-f3Ur0L8

<modules>
<load name="ins_chimu_spi.xml" />
</modules>

...

<subsystem name="spi_slave_hs"/>

Use CHIMU with simple uart connection on both lisa or tiny/twog

<modules>
<load name="ins_chimu_uart.xml">
<configure name="CHIMU_UART_NR" value="0"/>
</load>
</modules>

=== SparkFun Razor 6DOF IMU ===

[[Image:RazzorIMU.jpg|thumb|left|Razor IMU (top) with the tiny13 autopilot]]

[[Image:RazzorIMUb.jpg|thumb|left|Razor IMU in the tiny13 autopilot box]]

[http://www.sparkfun.com/commerce/product_info.php?products_id=10010 Official website]

6DOF - Ultra-Thin IMU

Very cheap, currently 62-72 Euro. [http://www.watterott.com/de/Sensoren/IMU Shop in Europe]

Has been integrated in Paparazzi by using the DCM algorihm by Hochschule Bremen, Germany.

Remove the high pass filters of the RazorIMU to get better results.

For the Twog and Tiny 2.2 autopilots you have also remove the resistors to GND and the series resistors to the MC of the 5V analog inputs. The code to fly normal plane is currently in the repository. Christoph is working on improvements look here: http://paparazzi.enac.fr/wiki/User:Christoph

[[Media:Wiring_Razor_IMU.pdf|Connections and wiring to the tiny13]]

 

=== Drotek MPU6050 ===

[[Image:drotek1.jpg|thumb|left|component side]]
[[Image:drotek2.jpg|thumb|left|solder side]]

IMU Drotek MPU6050 - 6 Degrees of Freedom Invensens MPU6050

http://www.drotek.fr/shop/en/42-mpu6050-gyro-accelerometer.html

Tiny, very low cost < 13 Euro , 5V and 3.3V input, I2C interface.

This IMU has been tested for TWOG, Tiny 1.3, HBmini, Umarin, YAPA and flown with YAPA.
Note that this sensor use the alternative I2C address. Correct is in the driver file. It is a low cost and precise solution for normal aircraft.

 

=== Drotek MPU6050-hmc5883-ms5611 ===

[[Image:drotek3.jpg|thumb|left|component side]]
[[Image:drotek4.jpg|thumb|left|solder side]]

IMU Drotek MPU6050 - 10 Degrees of Freedom

http://www.drotek.fr/shop/en/62-imu-10dof-mpu6050-hmc5883-ms5611.html

Tiny, low cost < 36 Euro , 5V and 3.3V input, I2C interface.

Note that the MPU6050 sensor use the alternative I2C address and that the hmc5883 ms5611 are connected
to the autopilot I2C bus. Correct the address in the driver file of the MPU6050. Use the separate HMC5883 and ms5611 sensor drivers.
It is a low cost and precise solution for normal aircraft with a excellent baro sensor.

 

=== SparkFun SEN-10121 ===
[[Image:SEN-10121.jpg|thumb|left|SEN-10121]]

IMU Digital Combo Board - 6 Degrees of Freedom ITG3200/ADXL345

http://www.sparkfun.com/products/10121

Tiny, ADXL345 accelerometer, ITG-3200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with Tiny v2.11 and TWOG. It is very similar to the PPZUAV IMU.

Details of [[IMU/SEN-10121|configuration]].

 

=== Pololu MinIMU-9 ===
[[Image:MinIMU9.jpg|thumb|left|MinIMU-9]]

IMU Digital Combo Board - 9 Degrees of Freedom L3G4200/LSM303

http://www.pololu.com/catalog/product/1265

Tiny, LSM303 accelerometer and magnetometer, L3G4200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with TWOG.

Details of [[IMU/MinIMU-9|configuration]].

 

=== Cloudcap Crista IMU ===
[[Image:crista_sensorhead.jpg|thumb|left|Christa IMU]]

[http://www.cloudcaptech.com/crista_sensorhead.shtm Official website]

More infos soon.

 

== 3rd Party INS ==

INS measure rates with their sensors and run algorithms to estimate the state on their own. They give this information the the autopilot (e.g. Euler angles) that can then use it for navigation.

===[http://diydrones.com/profiles/blogs/arduimu-v2-flat-now-available|DIYDrones ArduIMU+ V2 (Flat)] ===
[[Image:ArduIMU.jpg|thumb|left|ArduIMU]]

[http://code.google.com/p/ardu-imu/wiki/HomePage?tm=6 Official website]

[[ArduIMU|Paparazzi Wiki Page]]

* 3 axis accelerometer + 3 axis gyroscope
* Low cost
* Has been integrated in Paparazzi by ZHAW, Winterthur, Switzerland.
* A magnetometer has been integrated in the software to compensate drift in yaw.
* GPS data from the Tiny is passed over I2C to the AHRS on the IMU.
* Is sold by [http://www.sparkfun.com/products/9956 Sparkfun] and [http://store.diydrones.com/ProductDetails.asp?ProductCode=KT-ArduIMU-20 DIYDrones Store].
 

=== Vector-Nav VN-100 ===
[[Image:VN-100.jpg|thumb|left|Vector-Nav VN-100]]

[http://www.vectornav.com/vn-100-features Official website]

There is a [[Modules|module]] for this AHRS (ins_vn100.xml for fixedwings).

 

=== MicroStrain 3DM-GX2 ===
[[Image:3DM-GX2.jpg|thumb|left|MicroStrain 3DM-GX2]]

[http://www.microstrain.com/3dm-gx2.aspx Official website]

More info soon.

 

=== Xsens MTi and MTi-G (with GPS) ===
[[Image:MTi.jpeg|thumb|left|Xsens MTi]]

[[Image:MTi-G.jpeg|thumb|left|Xsens MTi-G (with GPS)]]

[http://www.xsens.com/en/general/mti Official website MTi]

[http://www.xsens.com/en/general/mti-g Official website MTi-G]

In sensor fusion, calibration and timing are crucial. If you want latency compensated ADXRS gyro integrated attitude done by an efficient and optimized Blackfin DSP you need an XSens. For rotorcraft the 100Hz is a bit slow, but for fixedwing it's perfect. Directly compatible with [[Yapa]] and [[Lisa]] and all needed code in paparazi.

 

=== MemSense MAG3 ===

MAG3 - 6 DOF Analog IMU with Triaxial Magnetometer

[http://www.memsense.com/index.php/Product-Pages/mag3-worlds-smallest-analog-inertial-measurement-unit.html Official website mag3]

== The Very Short Essential Introduction To Inertial Attitude Estimation ==

The only physical entity related to attitude (pitch and roll) is the earth gravity vector (unless you use a multi-antenna phase-measuring GPS... $$$$). Unfortunately, the sensors that measure gravity (=accelerometers) also measure so-called kinematic accelerations or in other words: changes in speed: like centrifugal forces, Coriolis forces, linear accelerations etc... The sum of all these litteraly is "what you feel" and is called [http://en.wikipedia.org/wiki/Specific_force "specific force"].

so

accelerometer_value (specific force) = earth_gravity + change in velocity (linear accelerations) + velocity times turn rate (centrifugal etc)

or

A = B + C + D

You measure A and want to know B. What all "gyroscopes and accelerometer only" AHRS projects are doing in some way or another is to neglect the last 2 (C and D). In many situations this is not bad: for instance: when testing the AHRS attached to your computer: it can not accelerate for a very long time (at most a few meters: so if you accerate to the left, then you need to accelerate to the right directly after so the average is zero) and can not rotate to much either (or your cable gets strangled). This is why all AHRS videos on youtube look perfect. And on the desk they are perfect: you neglected 2 terms in the equation that in that situation are perfectly neglect-able. Also with a quadrotor that hovers and keeps its nose in the same direction all the time, these neglected terms are small.

Now what about the gyroscopes you might ask. I deliberately keep them only second as gyroscopes (turn rate or rotation speed sensors) do NOT give you attitude but ONLY HELP TO SOLVE SHORT TERM errors in the previous part. If gyroscopes would measure turn-rate perfectly, then they would help more but all MEMS/PIEZZO sensors are more or less sensitive to 1) temperature, 2) turnrate, 3) vibrations, 4) accelerations, 5) radiation, 6) power supply quality 7) non-linearity 8) ADC-quality 9) dynamic range and saturation problems, ... so if you integrate gyroscopes, sooner or later errors build up (drift). I put this list here so you know what to pay attention for: if using gyroscopes: always try to keep the temperature as constant as possible or let the temperature settle, reduce vibrations (dampers), use better ADC (e.g. 10bit ADC with +/- 1200 deg/sec gyros have a resolution of 2.4 degrees/s per ADC tick, so your phi/theta might drift 1.2deg/sec without noticing) and power supply filtering and shielding etc to start with. All of these define for how long (seconds!/minutes?) gyroscope integration is useful.

If you convert the accelerometer directly to attitude and plot it, it will vibrate a lot and will show errors when you accelerate the AHRS on your desk. During a coordinated turn of a fixedwing plane, the force you feel is perpendicular to the plane (not pointing to earth). The accelerometer only clearly is insufficient to know your attitude. One solution is to use gyroscopes that are so good that you can predict for many minutes (then the average acceleration during several turns would still point to earth). But if your gyros can only help for shorter terms (like all MEMS sensors of less than 500euro/each) then extra information is required. E.g: if you add GPS data or airspeed data however, from the flightpath you can quite accurately reconstruct the missing C and D terms. Together with the accelerometer you can know "where the earth is" even when you keep accelerating and turning. Here questions like latency, update rate, noisy derivatives (linear acceleration) are of importance.

Finally there is the heading... GPS ground-track is not the same as nose direction. Gyroscopes measure how much the nose has been turning, so using GPS to correct it induces errors that increase with corsswind. Magnetometers can help here, and become necessary whenever you do not move enough anymore (hovering). This situation can also occur in plane flying in very strong winds.

See the [[Subsystem/ahrs|AHRS subsystem]] page for an overview of some algorithm implementations.

[[Category:Sensors]]

Sensors/IMU

2013-02-08T11:49:31Z

Hwarm: /* Drotek MPU6050 */

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Sensors</categorytree>
__TOC__
'''See the [[Subsystem/imu|IMU subsystem]] page for the software drivers.'''
== Terminology ==
* '''IMU''': inertial measurement unit: only measures the accelerations and rotation rates (and magnetic field)
* '''AHRS''': attitude and heading reference system: uses IMU data + extra (airspeed/GPS/baro/...) to do sensor fusion and provide pitch and roll
* '''INS''': integrated navigation system: uses IMU + Navigation sensor(s) (e.g. GPS) + even more complex algorithms that besides pitch and roll also interpolates positions and velocities using the attitude corrected acceleration measurements.

== Paparazzi IMUs ==

=== Booz IMU v 1.01 ===

*High quality analog devices sensors
*16bit ADC capable of 200 000 samples per second
*Special attention to clean power with onboard linear supplies
*Efficient high-speed SPI for minimal microcontroller overhead and ultra-low latency (=better controller performance).
*Fits on Booz, Lisa AND Tiny/TWOG autopilots.

While originally designed for use with rotorcrafts, code is now available for use with fixed wing.

[[Image:IMU001.jpg|240px]]

The hardware description is [[BoozIMU|here]].

Available at [https://mini.ppzuav.com/osc/product_info.php?cPath=15&products_id=122&osCsid=bq9cget2u5c7ksa6kd9ssdf03lisuksq PPZUAV].

=== YAI v1.0 ===

Why "yet another imu" while there are already so many out there?

[[Image:yai_assemb.jpg|240px]]

*Designed to be completely compatible with original booz IMU and its code
*Cheaper sensors (lower bias stability)
*Higher resolution (16bits) and frequency (200ksps) and cleaner onboard power supply, better grounding and shielding than compared with e.g. external sparkfun breakout boards
*Fast low latency SPI communication (no uart as the tiny/twog miss uarts)
*The most important part of attitude determination is proper kinematic compensation using for instance GPS, pressure sensors etc etc. When using IMU with external processors there is often less flexibility. Things as timing for instance are as important as the quality of the gyros themselves.

Board, BOM -> [ http://svn.savannah.nongnu.org/viewvc/paparazzi-hardware/trunk/sensors/yai/?root=paparazzi Hardware Repository]

=== Aspirin IMU ===

[[Image:Aspirin_imu_front.jpg|240px]]

[[AspirinIMU|Next generation flat imu.]] This little imu with latest generation of integrated high rate high resolution gyros's moreover has very low noise and stable power supplies and outputs all sensors interrupt pins for optimal performance.

Note: while the main intended use is the very low latency high performance spi+i2c+interrupts connection (e.g. on lisa/M), please note that aspirin v2 can also be used with any tiny/twog for fixedwing aircraft with the same 4-wire interface and identical software as the PPZUAV-IMU. (connect Aspirin-SCK and aspirin-SCL to the I2C-SCL, aspirin-mosi and aspirin-SDA to I2C-SDA, Vcc to 5V (preferably linear), aspirin-gnd and aspirin-miso to GND, and aspirin-CS to 3.3V.)

Detailed information about the [[AspirinIMU|Aspirin IMU]] is available [[AspirinIMU|here.]]

== 3rd Party IMU ==

'''Loose Terminology Note:''' Like the sparkfun website, the following text incorrectly equates the term "degree-of-freedom" with sensor measurement. Unless we're talking about articulated arms (which paparazzi to date isn't involved with), a body can only have 6 physical DOFs and that would correspond to translation and rotations in the x,y,z cartesian directions of 3D space. If the vehicle state vector includes positions and velocities for each degree of freedom, the state vector would have a dimension of 6 x 2 = 12 states. The goal is to reconstruct these vehicle states using sensor measurements, as once the states can be obtained with reasonable certainty, a control algorithm can have a shot at controlling the system. Using various filtering techniques, multiple sensor types can be combined to estimate these states.

IMU's measure rotation rates, acceleration (6DOF) and some also magnetic fields (9DOF). This data is used by an autopilot to estimate the state of the aircraft. They that can be used with a Paparazzi autopilot based UAS. If you happen to have such a device, we really would love to see that you share your IMU paparazzi autopilot integration projects information on this Wiki.

=== PPZUAV IMU 9DOF ===
<gallery>
Image:Ppz9dofimu.jpg|9DOM IMU
Image:Ppz9dofimumed.jpg|Example Wiring to Tiny2.11
Image:Ppz9domschematic.jpg|Schematic
</gallery>


Another IMU based around the ITG-3200, ADXL345 and HMC5843. 
Features: I2C out 5v input. Interrupts . 
PCBs available from PPZUAV (assemblies soon). Schematic open, design is Altium Designer, gerbers available. 


A sample airframe illustrating all calibration issues and reading and merging the sensor at 100Hz with minimal control delays is in the repository to get you started:

airframe: PPZUAV/fixedwing/tiny_imu.xml
settings: tuning_basic_ins.xml
telemetry: default_fixedwing_imu.xml

Credit and thanks go out to Christophe for making the code and testing.

Media
YouTube: http://www.youtube.com/watch?v=OaMTyJ-s-PU
 

=== Ryan Mechatronics CHIMU AHRS ===

Very nice product: using the ultra high speed ultra low latency 200Hz SPI-slave mode (even 200Hz innerloop control of fixedwing is possible) or simple 4-wire connection via serial port to any TWOG/TINY/LISA/YAPA.

Don't want to spend time testing AHRS filters? Nor calibrating IMU? This module with molex connector can be bought calibrated and does all the filtering internally.

Use it with highspeed SPI on LPC-based boards: http://www.youtube.com/watch?v=mxx-f3Ur0L8

<modules>
<load name="ins_chimu_spi.xml" />
</modules>

...

<subsystem name="spi_slave_hs"/>

Use CHIMU with simple uart connection on both lisa or tiny/twog

<modules>
<load name="ins_chimu_uart.xml">
<configure name="CHIMU_UART_NR" value="0"/>
</load>
</modules>

=== SparkFun Razor 6DOF IMU ===

[[Image:RazzorIMU.jpg|thumb|left|Razor IMU (top) with the tiny13 autopilot]]

[[Image:RazzorIMUb.jpg|thumb|left|Razor IMU in the tiny13 autopilot box]]

[http://www.sparkfun.com/commerce/product_info.php?products_id=10010 Official website]

6DOF - Ultra-Thin IMU

Very cheap, currently 62-72 Euro. [http://www.watterott.com/de/Sensoren/IMU Shop in Europe]

Has been integrated in Paparazzi by using the DCM algorihm by Hochschule Bremen, Germany.

Remove the high pass filters of the RazorIMU to get better results.

For the Twog and Tiny 2.2 autopilots you have also remove the resistors to GND and the series resistors to the MC of the 5V analog inputs. The code to fly normal plane is currently in the repository. Christoph is working on improvements look here: http://paparazzi.enac.fr/wiki/User:Christoph

[[Media:Wiring_Razor_IMU.pdf|Connections and wiring to the tiny13]]

 

=== Drotek MPU6050 ===

[[Image:drotek1.jpg|thumb|left|component side]]
[[Image:drotek2.jpg|thumb|left|solder side]]

IMU Drotek MPU6050 - 6 Degrees of Freedom Invensens MPU6050

http://www.drotek.fr/shop/en/42-mpu6050-gyro-accelerometer.html

Tiny, very low cost < 13 Euro , 5V and 3.3V input, I2C interface.

This IMU has been tested for TWOG, Tiny 1.3, HBmini, Umarin, YAPA and flown with YAPA.
Note that this sensor use the alternative I2C address. Correct is in the driver file. It is a low cost and precise solution for normal aircraft.

 

=== SparkFun SEN-10121 ===
[[Image:SEN-10121.jpg|thumb|left|SEN-10121]]

IMU Digital Combo Board - 6 Degrees of Freedom ITG3200/ADXL345

http://www.sparkfun.com/products/10121

Tiny, ADXL345 accelerometer, ITG-3200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with Tiny v2.11 and TWOG. It is very similar to the PPZUAV IMU.

Details of [[IMU/SEN-10121|configuration]].

 

=== Pololu MinIMU-9 ===
[[Image:MinIMU9.jpg|thumb|left|MinIMU-9]]

IMU Digital Combo Board - 9 Degrees of Freedom L3G4200/LSM303

http://www.pololu.com/catalog/product/1265

Tiny, LSM303 accelerometer and magnetometer, L3G4200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with TWOG.

Details of [[IMU/MinIMU-9|configuration]].

 

=== Cloudcap Crista IMU ===
[[Image:crista_sensorhead.jpg|thumb|left|Christa IMU]]

[http://www.cloudcaptech.com/crista_sensorhead.shtm Official website]

More infos soon.

 

== 3rd Party INS ==

INS measure rates with their sensors and run algorithms to estimate the state on their own. They give this information the the autopilot (e.g. Euler angles) that can then use it for navigation.

===[http://diydrones.com/profiles/blogs/arduimu-v2-flat-now-available|DIYDrones ArduIMU+ V2 (Flat)] ===
[[Image:ArduIMU.jpg|thumb|left|ArduIMU]]

[http://code.google.com/p/ardu-imu/wiki/HomePage?tm=6 Official website]

[[ArduIMU|Paparazzi Wiki Page]]

* 3 axis accelerometer + 3 axis gyroscope
* Low cost
* Has been integrated in Paparazzi by ZHAW, Winterthur, Switzerland.
* A magnetometer has been integrated in the software to compensate drift in yaw.
* GPS data from the Tiny is passed over I2C to the AHRS on the IMU.
* Is sold by [http://www.sparkfun.com/products/9956 Sparkfun] and [http://store.diydrones.com/ProductDetails.asp?ProductCode=KT-ArduIMU-20 DIYDrones Store].
 

=== Vector-Nav VN-100 ===
[[Image:VN-100.jpg|thumb|left|Vector-Nav VN-100]]

[http://www.vectornav.com/vn-100-features Official website]

There is a [[Modules|module]] for this AHRS (ins_vn100.xml for fixedwings).

 

=== MicroStrain 3DM-GX2 ===
[[Image:3DM-GX2.jpg|thumb|left|MicroStrain 3DM-GX2]]

[http://www.microstrain.com/3dm-gx2.aspx Official website]

More info soon.

 

=== Xsens MTi and MTi-G (with GPS) ===
[[Image:MTi.jpeg|thumb|left|Xsens MTi]]

[[Image:MTi-G.jpeg|thumb|left|Xsens MTi-G (with GPS)]]

[http://www.xsens.com/en/general/mti Official website MTi]

[http://www.xsens.com/en/general/mti-g Official website MTi-G]

In sensor fusion, calibration and timing are crucial. If you want latency compensated ADXRS gyro integrated attitude done by an efficient and optimized Blackfin DSP you need an XSens. For rotorcraft the 100Hz is a bit slow, but for fixedwing it's perfect. Directly compatible with [[Yapa]] and [[Lisa]] and all needed code in paparazi.

 

=== MemSense MAG3 ===

MAG3 - 6 DOF Analog IMU with Triaxial Magnetometer

[http://www.memsense.com/index.php/Product-Pages/mag3-worlds-smallest-analog-inertial-measurement-unit.html Official website mag3]

== The Very Short Essential Introduction To Inertial Attitude Estimation ==

The only physical entity related to attitude (pitch and roll) is the earth gravity vector (unless you use a multi-antenna phase-measuring GPS... $$$$). Unfortunately, the sensors that measure gravity (=accelerometers) also measure so-called kinematic accelerations or in other words: changes in speed: like centrifugal forces, Coriolis forces, linear accelerations etc... The sum of all these litteraly is "what you feel" and is called [http://en.wikipedia.org/wiki/Specific_force "specific force"].

so

accelerometer_value (specific force) = earth_gravity + change in velocity (linear accelerations) + velocity times turn rate (centrifugal etc)

or

A = B + C + D

You measure A and want to know B. What all "gyroscopes and accelerometer only" AHRS projects are doing in some way or another is to neglect the last 2 (C and D). In many situations this is not bad: for instance: when testing the AHRS attached to your computer: it can not accelerate for a very long time (at most a few meters: so if you accerate to the left, then you need to accelerate to the right directly after so the average is zero) and can not rotate to much either (or your cable gets strangled). This is why all AHRS videos on youtube look perfect. And on the desk they are perfect: you neglected 2 terms in the equation that in that situation are perfectly neglect-able. Also with a quadrotor that hovers and keeps its nose in the same direction all the time, these neglected terms are small.

Now what about the gyroscopes you might ask. I deliberately keep them only second as gyroscopes (turn rate or rotation speed sensors) do NOT give you attitude but ONLY HELP TO SOLVE SHORT TERM errors in the previous part. If gyroscopes would measure turn-rate perfectly, then they would help more but all MEMS/PIEZZO sensors are more or less sensitive to 1) temperature, 2) turnrate, 3) vibrations, 4) accelerations, 5) radiation, 6) power supply quality 7) non-linearity 8) ADC-quality 9) dynamic range and saturation problems, ... so if you integrate gyroscopes, sooner or later errors build up (drift). I put this list here so you know what to pay attention for: if using gyroscopes: always try to keep the temperature as constant as possible or let the temperature settle, reduce vibrations (dampers), use better ADC (e.g. 10bit ADC with +/- 1200 deg/sec gyros have a resolution of 2.4 degrees/s per ADC tick, so your phi/theta might drift 1.2deg/sec without noticing) and power supply filtering and shielding etc to start with. All of these define for how long (seconds!/minutes?) gyroscope integration is useful.

If you convert the accelerometer directly to attitude and plot it, it will vibrate a lot and will show errors when you accelerate the AHRS on your desk. During a coordinated turn of a fixedwing plane, the force you feel is perpendicular to the plane (not pointing to earth). The accelerometer only clearly is insufficient to know your attitude. One solution is to use gyroscopes that are so good that you can predict for many minutes (then the average acceleration during several turns would still point to earth). But if your gyros can only help for shorter terms (like all MEMS sensors of less than 500euro/each) then extra information is required. E.g: if you add GPS data or airspeed data however, from the flightpath you can quite accurately reconstruct the missing C and D terms. Together with the accelerometer you can know "where the earth is" even when you keep accelerating and turning. Here questions like latency, update rate, noisy derivatives (linear acceleration) are of importance.

Finally there is the heading... GPS ground-track is not the same as nose direction. Gyroscopes measure how much the nose has been turning, so using GPS to correct it induces errors that increase with corsswind. Magnetometers can help here, and become necessary whenever you do not move enough anymore (hovering). This situation can also occur in plane flying in very strong winds.

See the [[Subsystem/ahrs|AHRS subsystem]] page for an overview of some algorithm implementations.

[[Category:Sensors]]

Sensors/IMU

2013-02-08T11:48:25Z

Hwarm: /* Drotek MPU6050 */

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Sensors</categorytree>
__TOC__
'''See the [[Subsystem/imu|IMU subsystem]] page for the software drivers.'''
== Terminology ==
* '''IMU''': inertial measurement unit: only measures the accelerations and rotation rates (and magnetic field)
* '''AHRS''': attitude and heading reference system: uses IMU data + extra (airspeed/GPS/baro/...) to do sensor fusion and provide pitch and roll
* '''INS''': integrated navigation system: uses IMU + Navigation sensor(s) (e.g. GPS) + even more complex algorithms that besides pitch and roll also interpolates positions and velocities using the attitude corrected acceleration measurements.

== Paparazzi IMUs ==

=== Booz IMU v 1.01 ===

*High quality analog devices sensors
*16bit ADC capable of 200 000 samples per second
*Special attention to clean power with onboard linear supplies
*Efficient high-speed SPI for minimal microcontroller overhead and ultra-low latency (=better controller performance).
*Fits on Booz, Lisa AND Tiny/TWOG autopilots.

While originally designed for use with rotorcrafts, code is now available for use with fixed wing.

[[Image:IMU001.jpg|240px]]

The hardware description is [[BoozIMU|here]].

Available at [https://mini.ppzuav.com/osc/product_info.php?cPath=15&products_id=122&osCsid=bq9cget2u5c7ksa6kd9ssdf03lisuksq PPZUAV].

=== YAI v1.0 ===

Why "yet another imu" while there are already so many out there?

[[Image:yai_assemb.jpg|240px]]

*Designed to be completely compatible with original booz IMU and its code
*Cheaper sensors (lower bias stability)
*Higher resolution (16bits) and frequency (200ksps) and cleaner onboard power supply, better grounding and shielding than compared with e.g. external sparkfun breakout boards
*Fast low latency SPI communication (no uart as the tiny/twog miss uarts)
*The most important part of attitude determination is proper kinematic compensation using for instance GPS, pressure sensors etc etc. When using IMU with external processors there is often less flexibility. Things as timing for instance are as important as the quality of the gyros themselves.

Board, BOM -> [ http://svn.savannah.nongnu.org/viewvc/paparazzi-hardware/trunk/sensors/yai/?root=paparazzi Hardware Repository]

=== Aspirin IMU ===

[[Image:Aspirin_imu_front.jpg|240px]]

[[AspirinIMU|Next generation flat imu.]] This little imu with latest generation of integrated high rate high resolution gyros's moreover has very low noise and stable power supplies and outputs all sensors interrupt pins for optimal performance.

Note: while the main intended use is the very low latency high performance spi+i2c+interrupts connection (e.g. on lisa/M), please note that aspirin v2 can also be used with any tiny/twog for fixedwing aircraft with the same 4-wire interface and identical software as the PPZUAV-IMU. (connect Aspirin-SCK and aspirin-SCL to the I2C-SCL, aspirin-mosi and aspirin-SDA to I2C-SDA, Vcc to 5V (preferably linear), aspirin-gnd and aspirin-miso to GND, and aspirin-CS to 3.3V.)

Detailed information about the [[AspirinIMU|Aspirin IMU]] is available [[AspirinIMU|here.]]

== 3rd Party IMU ==

'''Loose Terminology Note:''' Like the sparkfun website, the following text incorrectly equates the term "degree-of-freedom" with sensor measurement. Unless we're talking about articulated arms (which paparazzi to date isn't involved with), a body can only have 6 physical DOFs and that would correspond to translation and rotations in the x,y,z cartesian directions of 3D space. If the vehicle state vector includes positions and velocities for each degree of freedom, the state vector would have a dimension of 6 x 2 = 12 states. The goal is to reconstruct these vehicle states using sensor measurements, as once the states can be obtained with reasonable certainty, a control algorithm can have a shot at controlling the system. Using various filtering techniques, multiple sensor types can be combined to estimate these states.

IMU's measure rotation rates, acceleration (6DOF) and some also magnetic fields (9DOF). This data is used by an autopilot to estimate the state of the aircraft. They that can be used with a Paparazzi autopilot based UAS. If you happen to have such a device, we really would love to see that you share your IMU paparazzi autopilot integration projects information on this Wiki.

=== PPZUAV IMU 9DOF ===
<gallery>
Image:Ppz9dofimu.jpg|9DOM IMU
Image:Ppz9dofimumed.jpg|Example Wiring to Tiny2.11
Image:Ppz9domschematic.jpg|Schematic
</gallery>


Another IMU based around the ITG-3200, ADXL345 and HMC5843. 
Features: I2C out 5v input. Interrupts . 
PCBs available from PPZUAV (assemblies soon). Schematic open, design is Altium Designer, gerbers available. 


A sample airframe illustrating all calibration issues and reading and merging the sensor at 100Hz with minimal control delays is in the repository to get you started:

airframe: PPZUAV/fixedwing/tiny_imu.xml
settings: tuning_basic_ins.xml
telemetry: default_fixedwing_imu.xml

Credit and thanks go out to Christophe for making the code and testing.

Media
YouTube: http://www.youtube.com/watch?v=OaMTyJ-s-PU
 

=== Ryan Mechatronics CHIMU AHRS ===

Very nice product: using the ultra high speed ultra low latency 200Hz SPI-slave mode (even 200Hz innerloop control of fixedwing is possible) or simple 4-wire connection via serial port to any TWOG/TINY/LISA/YAPA.

Don't want to spend time testing AHRS filters? Nor calibrating IMU? This module with molex connector can be bought calibrated and does all the filtering internally.

Use it with highspeed SPI on LPC-based boards: http://www.youtube.com/watch?v=mxx-f3Ur0L8

<modules>
<load name="ins_chimu_spi.xml" />
</modules>

...

<subsystem name="spi_slave_hs"/>

Use CHIMU with simple uart connection on both lisa or tiny/twog

<modules>
<load name="ins_chimu_uart.xml">
<configure name="CHIMU_UART_NR" value="0"/>
</load>
</modules>

=== SparkFun Razor 6DOF IMU ===

[[Image:RazzorIMU.jpg|thumb|left|Razor IMU (top) with the tiny13 autopilot]]

[[Image:RazzorIMUb.jpg|thumb|left|Razor IMU in the tiny13 autopilot box]]

[http://www.sparkfun.com/commerce/product_info.php?products_id=10010 Official website]

6DOF - Ultra-Thin IMU

Very cheap, currently 62-72 Euro. [http://www.watterott.com/de/Sensoren/IMU Shop in Europe]

Has been integrated in Paparazzi by using the DCM algorihm by Hochschule Bremen, Germany.

Remove the high pass filters of the RazorIMU to get better results.

For the Twog and Tiny 2.2 autopilots you have also remove the resistors to GND and the series resistors to the MC of the 5V analog inputs. The code to fly normal plane is currently in the repository. Christoph is working on improvements look here: http://paparazzi.enac.fr/wiki/User:Christoph

[[Media:Wiring_Razor_IMU.pdf|Connections and wiring to the tiny13]]

 

=== Drotek MPU6050 ===

[[Image:drotek1.jpg|thumb|left|component side]]
[[Image:drotek2.jpg|thumb|left|solder side]]

IMU Drotek MPU6050 - 6 Degrees of Freedom Invensens MPU6050

http://www.drotek.fr/shop/en/42-mpu6050-gyro-accelerometer.html

Tiny, very low cost > 13 Euro , 5V and 3.3V input, I2C interface.

This IMU has been tested for TWOG, Tiny 1.3, HBmini, Umarin, YAPA and flown with YAPA.
Note that this sensor use the alternative I2C address. Correct is in the driver file. It is a low cost and precise solution for normal aircraft.

 

=== SparkFun SEN-10121 ===
[[Image:SEN-10121.jpg|thumb|left|SEN-10121]]

IMU Digital Combo Board - 6 Degrees of Freedom ITG3200/ADXL345

http://www.sparkfun.com/products/10121

Tiny, ADXL345 accelerometer, ITG-3200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with Tiny v2.11 and TWOG. It is very similar to the PPZUAV IMU.

Details of [[IMU/SEN-10121|configuration]].

 

=== Pololu MinIMU-9 ===
[[Image:MinIMU9.jpg|thumb|left|MinIMU-9]]

IMU Digital Combo Board - 9 Degrees of Freedom L3G4200/LSM303

http://www.pololu.com/catalog/product/1265

Tiny, LSM303 accelerometer and magnetometer, L3G4200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with TWOG.

Details of [[IMU/MinIMU-9|configuration]].

 

=== Cloudcap Crista IMU ===
[[Image:crista_sensorhead.jpg|thumb|left|Christa IMU]]

[http://www.cloudcaptech.com/crista_sensorhead.shtm Official website]

More infos soon.

 

== 3rd Party INS ==

INS measure rates with their sensors and run algorithms to estimate the state on their own. They give this information the the autopilot (e.g. Euler angles) that can then use it for navigation.

===[http://diydrones.com/profiles/blogs/arduimu-v2-flat-now-available|DIYDrones ArduIMU+ V2 (Flat)] ===
[[Image:ArduIMU.jpg|thumb|left|ArduIMU]]

[http://code.google.com/p/ardu-imu/wiki/HomePage?tm=6 Official website]

[[ArduIMU|Paparazzi Wiki Page]]

* 3 axis accelerometer + 3 axis gyroscope
* Low cost
* Has been integrated in Paparazzi by ZHAW, Winterthur, Switzerland.
* A magnetometer has been integrated in the software to compensate drift in yaw.
* GPS data from the Tiny is passed over I2C to the AHRS on the IMU.
* Is sold by [http://www.sparkfun.com/products/9956 Sparkfun] and [http://store.diydrones.com/ProductDetails.asp?ProductCode=KT-ArduIMU-20 DIYDrones Store].
 

=== Vector-Nav VN-100 ===
[[Image:VN-100.jpg|thumb|left|Vector-Nav VN-100]]

[http://www.vectornav.com/vn-100-features Official website]

There is a [[Modules|module]] for this AHRS (ins_vn100.xml for fixedwings).

 

=== MicroStrain 3DM-GX2 ===
[[Image:3DM-GX2.jpg|thumb|left|MicroStrain 3DM-GX2]]

[http://www.microstrain.com/3dm-gx2.aspx Official website]

More info soon.

 

=== Xsens MTi and MTi-G (with GPS) ===
[[Image:MTi.jpeg|thumb|left|Xsens MTi]]

[[Image:MTi-G.jpeg|thumb|left|Xsens MTi-G (with GPS)]]

[http://www.xsens.com/en/general/mti Official website MTi]

[http://www.xsens.com/en/general/mti-g Official website MTi-G]

In sensor fusion, calibration and timing are crucial. If you want latency compensated ADXRS gyro integrated attitude done by an efficient and optimized Blackfin DSP you need an XSens. For rotorcraft the 100Hz is a bit slow, but for fixedwing it's perfect. Directly compatible with [[Yapa]] and [[Lisa]] and all needed code in paparazi.

 

=== MemSense MAG3 ===

MAG3 - 6 DOF Analog IMU with Triaxial Magnetometer

[http://www.memsense.com/index.php/Product-Pages/mag3-worlds-smallest-analog-inertial-measurement-unit.html Official website mag3]

== The Very Short Essential Introduction To Inertial Attitude Estimation ==

The only physical entity related to attitude (pitch and roll) is the earth gravity vector (unless you use a multi-antenna phase-measuring GPS... $$$$). Unfortunately, the sensors that measure gravity (=accelerometers) also measure so-called kinematic accelerations or in other words: changes in speed: like centrifugal forces, Coriolis forces, linear accelerations etc... The sum of all these litteraly is "what you feel" and is called [http://en.wikipedia.org/wiki/Specific_force "specific force"].

so

accelerometer_value (specific force) = earth_gravity + change in velocity (linear accelerations) + velocity times turn rate (centrifugal etc)

or

A = B + C + D

You measure A and want to know B. What all "gyroscopes and accelerometer only" AHRS projects are doing in some way or another is to neglect the last 2 (C and D). In many situations this is not bad: for instance: when testing the AHRS attached to your computer: it can not accelerate for a very long time (at most a few meters: so if you accerate to the left, then you need to accelerate to the right directly after so the average is zero) and can not rotate to much either (or your cable gets strangled). This is why all AHRS videos on youtube look perfect. And on the desk they are perfect: you neglected 2 terms in the equation that in that situation are perfectly neglect-able. Also with a quadrotor that hovers and keeps its nose in the same direction all the time, these neglected terms are small.

Now what about the gyroscopes you might ask. I deliberately keep them only second as gyroscopes (turn rate or rotation speed sensors) do NOT give you attitude but ONLY HELP TO SOLVE SHORT TERM errors in the previous part. If gyroscopes would measure turn-rate perfectly, then they would help more but all MEMS/PIEZZO sensors are more or less sensitive to 1) temperature, 2) turnrate, 3) vibrations, 4) accelerations, 5) radiation, 6) power supply quality 7) non-linearity 8) ADC-quality 9) dynamic range and saturation problems, ... so if you integrate gyroscopes, sooner or later errors build up (drift). I put this list here so you know what to pay attention for: if using gyroscopes: always try to keep the temperature as constant as possible or let the temperature settle, reduce vibrations (dampers), use better ADC (e.g. 10bit ADC with +/- 1200 deg/sec gyros have a resolution of 2.4 degrees/s per ADC tick, so your phi/theta might drift 1.2deg/sec without noticing) and power supply filtering and shielding etc to start with. All of these define for how long (seconds!/minutes?) gyroscope integration is useful.

If you convert the accelerometer directly to attitude and plot it, it will vibrate a lot and will show errors when you accelerate the AHRS on your desk. During a coordinated turn of a fixedwing plane, the force you feel is perpendicular to the plane (not pointing to earth). The accelerometer only clearly is insufficient to know your attitude. One solution is to use gyroscopes that are so good that you can predict for many minutes (then the average acceleration during several turns would still point to earth). But if your gyros can only help for shorter terms (like all MEMS sensors of less than 500euro/each) then extra information is required. E.g: if you add GPS data or airspeed data however, from the flightpath you can quite accurately reconstruct the missing C and D terms. Together with the accelerometer you can know "where the earth is" even when you keep accelerating and turning. Here questions like latency, update rate, noisy derivatives (linear acceleration) are of importance.

Finally there is the heading... GPS ground-track is not the same as nose direction. Gyroscopes measure how much the nose has been turning, so using GPS to correct it induces errors that increase with corsswind. Magnetometers can help here, and become necessary whenever you do not move enough anymore (hovering). This situation can also occur in plane flying in very strong winds.

See the [[Subsystem/ahrs|AHRS subsystem]] page for an overview of some algorithm implementations.

[[Category:Sensors]]

Sensors/IMU

2013-02-08T11:45:27Z

Hwarm:

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Sensors</categorytree>
__TOC__
'''See the [[Subsystem/imu|IMU subsystem]] page for the software drivers.'''
== Terminology ==
* '''IMU''': inertial measurement unit: only measures the accelerations and rotation rates (and magnetic field)
* '''AHRS''': attitude and heading reference system: uses IMU data + extra (airspeed/GPS/baro/...) to do sensor fusion and provide pitch and roll
* '''INS''': integrated navigation system: uses IMU + Navigation sensor(s) (e.g. GPS) + even more complex algorithms that besides pitch and roll also interpolates positions and velocities using the attitude corrected acceleration measurements.

== Paparazzi IMUs ==

=== Booz IMU v 1.01 ===

*High quality analog devices sensors
*16bit ADC capable of 200 000 samples per second
*Special attention to clean power with onboard linear supplies
*Efficient high-speed SPI for minimal microcontroller overhead and ultra-low latency (=better controller performance).
*Fits on Booz, Lisa AND Tiny/TWOG autopilots.

While originally designed for use with rotorcrafts, code is now available for use with fixed wing.

[[Image:IMU001.jpg|240px]]

The hardware description is [[BoozIMU|here]].

Available at [https://mini.ppzuav.com/osc/product_info.php?cPath=15&products_id=122&osCsid=bq9cget2u5c7ksa6kd9ssdf03lisuksq PPZUAV].

=== YAI v1.0 ===

Why "yet another imu" while there are already so many out there?

[[Image:yai_assemb.jpg|240px]]

*Designed to be completely compatible with original booz IMU and its code
*Cheaper sensors (lower bias stability)
*Higher resolution (16bits) and frequency (200ksps) and cleaner onboard power supply, better grounding and shielding than compared with e.g. external sparkfun breakout boards
*Fast low latency SPI communication (no uart as the tiny/twog miss uarts)
*The most important part of attitude determination is proper kinematic compensation using for instance GPS, pressure sensors etc etc. When using IMU with external processors there is often less flexibility. Things as timing for instance are as important as the quality of the gyros themselves.

Board, BOM -> [ http://svn.savannah.nongnu.org/viewvc/paparazzi-hardware/trunk/sensors/yai/?root=paparazzi Hardware Repository]

=== Aspirin IMU ===

[[Image:Aspirin_imu_front.jpg|240px]]

[[AspirinIMU|Next generation flat imu.]] This little imu with latest generation of integrated high rate high resolution gyros's moreover has very low noise and stable power supplies and outputs all sensors interrupt pins for optimal performance.

Note: while the main intended use is the very low latency high performance spi+i2c+interrupts connection (e.g. on lisa/M), please note that aspirin v2 can also be used with any tiny/twog for fixedwing aircraft with the same 4-wire interface and identical software as the PPZUAV-IMU. (connect Aspirin-SCK and aspirin-SCL to the I2C-SCL, aspirin-mosi and aspirin-SDA to I2C-SDA, Vcc to 5V (preferably linear), aspirin-gnd and aspirin-miso to GND, and aspirin-CS to 3.3V.)

Detailed information about the [[AspirinIMU|Aspirin IMU]] is available [[AspirinIMU|here.]]

== 3rd Party IMU ==

'''Loose Terminology Note:''' Like the sparkfun website, the following text incorrectly equates the term "degree-of-freedom" with sensor measurement. Unless we're talking about articulated arms (which paparazzi to date isn't involved with), a body can only have 6 physical DOFs and that would correspond to translation and rotations in the x,y,z cartesian directions of 3D space. If the vehicle state vector includes positions and velocities for each degree of freedom, the state vector would have a dimension of 6 x 2 = 12 states. The goal is to reconstruct these vehicle states using sensor measurements, as once the states can be obtained with reasonable certainty, a control algorithm can have a shot at controlling the system. Using various filtering techniques, multiple sensor types can be combined to estimate these states.

IMU's measure rotation rates, acceleration (6DOF) and some also magnetic fields (9DOF). This data is used by an autopilot to estimate the state of the aircraft. They that can be used with a Paparazzi autopilot based UAS. If you happen to have such a device, we really would love to see that you share your IMU paparazzi autopilot integration projects information on this Wiki.

=== PPZUAV IMU 9DOF ===
<gallery>
Image:Ppz9dofimu.jpg|9DOM IMU
Image:Ppz9dofimumed.jpg|Example Wiring to Tiny2.11
Image:Ppz9domschematic.jpg|Schematic
</gallery>


Another IMU based around the ITG-3200, ADXL345 and HMC5843. 
Features: I2C out 5v input. Interrupts . 
PCBs available from PPZUAV (assemblies soon). Schematic open, design is Altium Designer, gerbers available. 


A sample airframe illustrating all calibration issues and reading and merging the sensor at 100Hz with minimal control delays is in the repository to get you started:

airframe: PPZUAV/fixedwing/tiny_imu.xml
settings: tuning_basic_ins.xml
telemetry: default_fixedwing_imu.xml

Credit and thanks go out to Christophe for making the code and testing.

Media
YouTube: http://www.youtube.com/watch?v=OaMTyJ-s-PU
 

=== Ryan Mechatronics CHIMU AHRS ===

Very nice product: using the ultra high speed ultra low latency 200Hz SPI-slave mode (even 200Hz innerloop control of fixedwing is possible) or simple 4-wire connection via serial port to any TWOG/TINY/LISA/YAPA.

Don't want to spend time testing AHRS filters? Nor calibrating IMU? This module with molex connector can be bought calibrated and does all the filtering internally.

Use it with highspeed SPI on LPC-based boards: http://www.youtube.com/watch?v=mxx-f3Ur0L8

<modules>
<load name="ins_chimu_spi.xml" />
</modules>

...

<subsystem name="spi_slave_hs"/>

Use CHIMU with simple uart connection on both lisa or tiny/twog

<modules>
<load name="ins_chimu_uart.xml">
<configure name="CHIMU_UART_NR" value="0"/>
</load>
</modules>

=== SparkFun Razor 6DOF IMU ===

[[Image:RazzorIMU.jpg|thumb|left|Razor IMU (top) with the tiny13 autopilot]]

[[Image:RazzorIMUb.jpg|thumb|left|Razor IMU in the tiny13 autopilot box]]

[http://www.sparkfun.com/commerce/product_info.php?products_id=10010 Official website]

6DOF - Ultra-Thin IMU

Very cheap, currently 62-72 Euro. [http://www.watterott.com/de/Sensoren/IMU Shop in Europe]

Has been integrated in Paparazzi by using the DCM algorihm by Hochschule Bremen, Germany.

Remove the high pass filters of the RazorIMU to get better results.

For the Twog and Tiny 2.2 autopilots you have also remove the resistors to GND and the series resistors to the MC of the 5V analog inputs. The code to fly normal plane is currently in the repository. Christoph is working on improvements look here: http://paparazzi.enac.fr/wiki/User:Christoph

[[Media:Wiring_Razor_IMU.pdf|Connections and wiring to the tiny13]]

 

=== Drotek MPU6050 ===

[[Image:drotek1.jpg|thumb|left|component side]]
[[Image:drotek2.jpg|thumb|left|solder side]]

IMU Drotek MPU6050 - 6 Degrees of Freedom InvensensMPU6050

http://www.drotek.fr/shop/en/42-mpu6050-gyro-accelerometer.html

Tiny, very low cost > 13 Euro , 5V and 3.3V input, I2C interface.

This IMU has been tested for TWOG Tiny 1.3 HBmini, Umarin, YAPA and flown with YAPA.
Note that this sensor use the alternative I2C address. It is a low cost solution for normal aircraft.

 

=== SparkFun SEN-10121 ===
[[Image:SEN-10121.jpg|thumb|left|SEN-10121]]

IMU Digital Combo Board - 6 Degrees of Freedom ITG3200/ADXL345

http://www.sparkfun.com/products/10121

Tiny, ADXL345 accelerometer, ITG-3200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with Tiny v2.11 and TWOG. It is very similar to the PPZUAV IMU.

Details of [[IMU/SEN-10121|configuration]].

 

=== Pololu MinIMU-9 ===
[[Image:MinIMU9.jpg|thumb|left|MinIMU-9]]

IMU Digital Combo Board - 9 Degrees of Freedom L3G4200/LSM303

http://www.pololu.com/catalog/product/1265

Tiny, LSM303 accelerometer and magnetometer, L3G4200 gyro, 3.3V input, I2C interface.

This IMU has been tested and flown with TWOG.

Details of [[IMU/MinIMU-9|configuration]].

 

=== Cloudcap Crista IMU ===
[[Image:crista_sensorhead.jpg|thumb|left|Christa IMU]]

[http://www.cloudcaptech.com/crista_sensorhead.shtm Official website]

More infos soon.

 

== 3rd Party INS ==

INS measure rates with their sensors and run algorithms to estimate the state on their own. They give this information the the autopilot (e.g. Euler angles) that can then use it for navigation.

===[http://diydrones.com/profiles/blogs/arduimu-v2-flat-now-available|DIYDrones ArduIMU+ V2 (Flat)] ===
[[Image:ArduIMU.jpg|thumb|left|ArduIMU]]

[http://code.google.com/p/ardu-imu/wiki/HomePage?tm=6 Official website]

[[ArduIMU|Paparazzi Wiki Page]]

* 3 axis accelerometer + 3 axis gyroscope
* Low cost
* Has been integrated in Paparazzi by ZHAW, Winterthur, Switzerland.
* A magnetometer has been integrated in the software to compensate drift in yaw.
* GPS data from the Tiny is passed over I2C to the AHRS on the IMU.
* Is sold by [http://www.sparkfun.com/products/9956 Sparkfun] and [http://store.diydrones.com/ProductDetails.asp?ProductCode=KT-ArduIMU-20 DIYDrones Store].
 

=== Vector-Nav VN-100 ===
[[Image:VN-100.jpg|thumb|left|Vector-Nav VN-100]]

[http://www.vectornav.com/vn-100-features Official website]

There is a [[Modules|module]] for this AHRS (ins_vn100.xml for fixedwings).

 

=== MicroStrain 3DM-GX2 ===
[[Image:3DM-GX2.jpg|thumb|left|MicroStrain 3DM-GX2]]

[http://www.microstrain.com/3dm-gx2.aspx Official website]

More info soon.

 

=== Xsens MTi and MTi-G (with GPS) ===
[[Image:MTi.jpeg|thumb|left|Xsens MTi]]

[[Image:MTi-G.jpeg|thumb|left|Xsens MTi-G (with GPS)]]

[http://www.xsens.com/en/general/mti Official website MTi]

[http://www.xsens.com/en/general/mti-g Official website MTi-G]

In sensor fusion, calibration and timing are crucial. If you want latency compensated ADXRS gyro integrated attitude done by an efficient and optimized Blackfin DSP you need an XSens. For rotorcraft the 100Hz is a bit slow, but for fixedwing it's perfect. Directly compatible with [[Yapa]] and [[Lisa]] and all needed code in paparazi.

 

=== MemSense MAG3 ===

MAG3 - 6 DOF Analog IMU with Triaxial Magnetometer

[http://www.memsense.com/index.php/Product-Pages/mag3-worlds-smallest-analog-inertial-measurement-unit.html Official website mag3]

== The Very Short Essential Introduction To Inertial Attitude Estimation ==

The only physical entity related to attitude (pitch and roll) is the earth gravity vector (unless you use a multi-antenna phase-measuring GPS... $$$$). Unfortunately, the sensors that measure gravity (=accelerometers) also measure so-called kinematic accelerations or in other words: changes in speed: like centrifugal forces, Coriolis forces, linear accelerations etc... The sum of all these litteraly is "what you feel" and is called [http://en.wikipedia.org/wiki/Specific_force "specific force"].

so

accelerometer_value (specific force) = earth_gravity + change in velocity (linear accelerations) + velocity times turn rate (centrifugal etc)

or

A = B + C + D

You measure A and want to know B. What all "gyroscopes and accelerometer only" AHRS projects are doing in some way or another is to neglect the last 2 (C and D). In many situations this is not bad: for instance: when testing the AHRS attached to your computer: it can not accelerate for a very long time (at most a few meters: so if you accerate to the left, then you need to accelerate to the right directly after so the average is zero) and can not rotate to much either (or your cable gets strangled). This is why all AHRS videos on youtube look perfect. And on the desk they are perfect: you neglected 2 terms in the equation that in that situation are perfectly neglect-able. Also with a quadrotor that hovers and keeps its nose in the same direction all the time, these neglected terms are small.

Now what about the gyroscopes you might ask. I deliberately keep them only second as gyroscopes (turn rate or rotation speed sensors) do NOT give you attitude but ONLY HELP TO SOLVE SHORT TERM errors in the previous part. If gyroscopes would measure turn-rate perfectly, then they would help more but all MEMS/PIEZZO sensors are more or less sensitive to 1) temperature, 2) turnrate, 3) vibrations, 4) accelerations, 5) radiation, 6) power supply quality 7) non-linearity 8) ADC-quality 9) dynamic range and saturation problems, ... so if you integrate gyroscopes, sooner or later errors build up (drift). I put this list here so you know what to pay attention for: if using gyroscopes: always try to keep the temperature as constant as possible or let the temperature settle, reduce vibrations (dampers), use better ADC (e.g. 10bit ADC with +/- 1200 deg/sec gyros have a resolution of 2.4 degrees/s per ADC tick, so your phi/theta might drift 1.2deg/sec without noticing) and power supply filtering and shielding etc to start with. All of these define for how long (seconds!/minutes?) gyroscope integration is useful.

If you convert the accelerometer directly to attitude and plot it, it will vibrate a lot and will show errors when you accelerate the AHRS on your desk. During a coordinated turn of a fixedwing plane, the force you feel is perpendicular to the plane (not pointing to earth). The accelerometer only clearly is insufficient to know your attitude. One solution is to use gyroscopes that are so good that you can predict for many minutes (then the average acceleration during several turns would still point to earth). But if your gyros can only help for shorter terms (like all MEMS sensors of less than 500euro/each) then extra information is required. E.g: if you add GPS data or airspeed data however, from the flightpath you can quite accurately reconstruct the missing C and D terms. Together with the accelerometer you can know "where the earth is" even when you keep accelerating and turning. Here questions like latency, update rate, noisy derivatives (linear acceleration) are of importance.

Finally there is the heading... GPS ground-track is not the same as nose direction. Gyroscopes measure how much the nose has been turning, so using GPS to correct it induces errors that increase with corsswind. Magnetometers can help here, and become necessary whenever you do not move enough anymore (hovering). This situation can also occur in plane flying in very strong winds.

See the [[Subsystem/ahrs|AHRS subsystem]] page for an overview of some algorithm implementations.

[[Category:Sensors]]

File:Drotek2.jpg

2013-02-08T10:10:48Z

Hwarm:

2011-03-23T09:16:14Z

Hwarm: /* SparkFun Razor 6DOF IMU */

== Paparazzi IMU ==

=== Booz IMU v 1.2 ===

*High quality analog devices sensors
*16bit ADC capable of 200 000 samples per second
*Special attention to clean power with onboard linear supplies
*Efficient high-speed SPI for minimal microcontroller overhead and ultra-low latency (=better controller performance).
*Fits on Booz, Lisa AND Tiny/TWOG autopilots.

While designed for booz, the first kalman filters were added to the fixedwing code for the Tiny autopilots.

[[Image:IMU001.jpg|240px]]

The hardware description is [[BoozIMU|here]].

Available at [https://mini.ppzuav.com/osc/product_info.php?cPath=15&products_id=122&osCsid=bq9cget2u5c7ksa6kd9ssdf03lisuksq PPZUAV].
The first IMU have been assembled and are being calibrated. Look for updates soon.

=== YAI v1.0 ===

Why "yet another imu" while there are already so many out there?

[[Image:yai_assemb.jpg|240px]]

*Designed to be completely compatible with original booz IMU and its code
*Cheaper sensors (lower bias stability)
*Higher resolution (16bits) and frequency (200ksps) and cleaner onboard power supply, better grounding and shielding than compared with e.g. external sparkfun breakout boards
*Fast low latency SPI communication (no uart as the tiny/twog miss uarts)
*The most important part of attitude determination is proper kinematic compensation using for instance GPS, pressure sensors etc etc. When using IMU with external processors there is often less flexibility. Things as timing for instance are as important as the quality of the gyros themselves.

Board, BOM -> [ http://svn.savannah.nongnu.org/viewvc/paparazzi-hardware/trunk/sensors/yai/?root=paparazzi Hardware Repository]

'''Error Note:''' Like the sparkfun website, the following text incorrectly equates the term "degree-of-freedom" with sensor measurement. Unless we're talking about articulated arms (which paparazzi to date isn't involved with), a body can only have 6 physical DOFs and that would correspond to translation and rotations in the x,y,z cartesian directions of 3D space. If the vehicle state vector includes positions and velocities for each degree of freedom, the state vector would have a dimension of 6 x 2 = 12 states. The goal is to reconstruct these vehicle states using sensor measurements, as once the states can be obtained with reasonable certainty, a control algorithm can have a shot at controlling the system. Using various filtering techniques, multiple sensor types can be combined to estimate these states.

=== Aspirin IMU ===

[[Image:Aspirin_imu_front.jpg|240px]]

[[AspirinIMU|Next generation flat imu.]]

== 3rd Party IMU ==

IMU's measure rotation rates, acceleration (6DOF) and some also magnetic fields (9DOF). This data is used by an autopilot to estimate the state of the aircraft. They that can be used with a Paparazzi autopilot based UAS. If you happen to have such a device, we really would love to see that you share your IMU paparazzi autopilot integration projects information on this Wiki.

=== PPZUAV IMU 9DOF ===

[[Image:Ppz9dofimu.jpg|thumb|left|PPZ 9DOF IMU]]

I2C out 5v input. Testing now. So far so good. It's open so anyone can have it now. PCBs available for a few dollars. Schematic open, design open but not in Eagle. I can post the gerbers.

 

=== SparkFun Razor 6DOF IMU ===

[[Image:RazzorIMU.jpg|thumb|left|Razor IMU (top) with the tiny13 autopilot]]

[[Image:RazzorIMUb.jpg|thumb|left|Razor IMU in the tiny13 autopilot box]]

[http://www.sparkfun.com/commerce/product_info.php?products_id=10010 Official website]

6DOF - Ultra-Thin IMU

Very cheap, currently 62-72 Euro. [http://www.watterott.com/de/Sensoren/IMU Shop in Europe]

Has been integrated in Paparazzi by Hochschule Bremen, Germany.

Remove the high pass filters of the RazorIMU to get better results.

For the Twog and Tiny 2.2 autopilots you have also remove the resistors to GND and the series resistors to the MC of the 5V analog inputs. The code to fly normal plane is currently in the repository. Christoph is working on improvements look here: http://paparazzi.enac.fr/wiki/User:Christoph

[[Media:Wiring_Razor_IMU.pdf|Connections and wiring to the tiny13]]

 

=== Cloudcap Crista IMU ===
[[Image:crista_sensorhead.jpg|thumb|left|Christa IMU]]

[http://www.cloudcaptech.com/crista_sensorhead.shtm Official website]

More infos soon.

 

== 3rd Party INS ==

INS measure rates with their sensors and run algorithms to estimate the state on their own. They give this information the the autopilot (e.g. Euler angles) that can then use it for navigation.

===[http://diydrones.com/profiles/blogs/arduimu-v2-flat-now-available|DIYDrones ArduIMU+ V2 (Flat)] ===
[[Image:ArduIMU.jpg|thumb|left|ArduIMU]]

[http://code.google.com/p/ardu-imu/wiki/HomePage?tm=6 Official website]
3 axis Accelerometer + 3 axis Gyroscope.

Very cheap
Has been integrated in Paparazzi by ZHAW, Winterthur, Switzerland.
* A magnetometer has been integrated in the software to compensate drift in yaw.
* GPS from the Tiny is passed over I2C to the AHRS on the IMU
More info on integration can be found [[ArduIMU|here]].
Where can I buy ArduIMU?
 
[http://www.sparkfun.com/products/9956 Sparkfun]
 
[http://store.diydrones.com/ProductDetails.asp?ProductCode=KT-ArduIMU-20 DIYDrones Store]
 

=== Vector-Nav VN-100 ===
[[Image:VN-100.jpg|thumb|left|Vector-Nav VN-100]]

[http://www.vectornav.com/vn-100-features Official website]

There is a [[Modules|module]] for this AHRS (ins_vn100.xml for fixedwings).

 

=== MicroStrain 3DM-GX2 ===
[[Image:3DM-GX2.jpg|thumb|left|MicroStrain 3DM-GX2]]

[http://www.microstrain.com/3dm-gx2.aspx Official website]

More info soon.

 

=== Xsens MTi and MTi-G (with GPS) ===
[[Image:MTi.jpeg|thumb|left|Xsens MTi]]

[[Image:MTi-G.jpeg|thumb|left|Xsens MTi-G (with GPS)]]

[http://www.xsens.com/en/general/mti Official website MTi]

[http://www.xsens.com/en/general/mti-g Official website MTi-G]

More info soon.

 

=== MemSense MAG3 ===

MAG3 - 6 DOF Analog IMU with Triaxial Magnetometer

[http://www.memsense.com/index.php/Product-Pages/mag3-worlds-smallest-analog-inertial-measurement-unit.html Official website mag3]

== The Very Short Essential Introduction To Inertial Attitude Estimation ==

The only physical entity related to attitude (pitch and roll) is the earth gravity vector (unless you use a multi-antenna phase-measuring GPS... $$$$). Unfortunately, the sensors that measure gravity (=accelerometers) also measure so-called kinematic accelerations or in other words: changes in speed: like centrifugal forces, Coriolis forces, linear accelerations etc... The sum of all these litteraly is "what you feel" and is called [http://en.wikipedia.org/wiki/Specific_force "specific force"].

so

accelerometer_value (specific force) = earth_gravity + change in velocity (linear accelerations) + velocity times turn rate (centrifugal etc)

or

A = B + C + D

You measure A and want to know B. What all "gyroscopes and accelerometer only" AHRS projects are doing in some way or another is to neglect the last 2 (C and D). In many situations this is not bad: for instance: when testing the AHRS attached to your computer: it can not accelerate for a very long time (at most a few meters: so if you accerate to the left, then you need to accelerate to the right directly after so the average is zero) and can not rotate to much either (or your cable gets strangled). This is why all AHRS videos on youtube look perfect. And on the desk they are perfect: you neglected 2 terms in the equation that in that situation are perfectly neglect-able. Also with a quadrotor that hovers and keeps its nose in the same direction all the time, these neglected terms are small.

Now what about the gyroscopes you might ask. I deliberately keep them only second as gyroscopes (turn rate or rotation speed sensors) do NOT give you attitude but ONLY HELP TO SOLVE SHORT TERM errors in the previous part. If gyroscopes would measure turn-rate perfectly, then they would help more but all MEMS/PIEZZO sensors are more or less sensitive to 1) temperature, 2) turnrate, 3) vibrations, 4) accelerations, 5) radiation, 6) power supply quality 7) non-linearity 8) ADC-quality 9) dynamic range and saturation problems, ... so if you integrate gyroscopes, sooner or later errors build up (drift). I put this list here so you know what to pay attention for: if using gyroscopes: always try to keep the temperature as constant as possible or let the temperature settle, reduce vibrations (dampers), use better ADC (e.g. 10bit ADC with +/- 1200 deg/sec gyros have a resolution of 2.4 degrees/s per ADC tick, so your phi/theta might drift 1.2deg/sec without noticing) and power supply filtering and shielding etc to start with. All of these define for how long (seconds!/minutes?) gyroscope integration is useful.

If you convert the accelerometer directly to attitude and plot it, it will vibrate a lot and will show errors when you accelerate the AHRS on your desk. During a coordinated turn of a fixedwing plane, the force you feel is perpendicular to the plane (not pointing to earth). The accelerometer only clearly is insufficient to know your attitude. One solution is to use gyroscopes that are so good that you can predict for many minutes (then the average acceleration during several turns would still point to earth). But if your gyros can only help for shorter terms (like all MEMS sensors of less than 500euro/each) then extra information is required. E.g: if you add GPS data or airspeed data however, from the flightpath you can quite accurately reconstruct the missing C and D terms. Together with the accelerometer you can know "where the earth is" even when you keep accelerating and turning. Here questions like latency, update rate, noisy derivatives (linear acceleration) are of importance.

Finally there is the heading... GPS ground-track is not the same as nose direction. Gyroscopes measure how much the nose has been turning, so using GPS to correct it induces errors that increase with corsswind. Magnetometers can help here, and become necessary whenever you do not move enough anymore (hovering). This situation can also occur in plane flying in very strong winds.

[[Category:Hardware]]

HB MINI

2011-03-23T09:03:23Z

Hwarm: /* HB-MINI-planar Autopilot */

=HB-MINI-planar Autopilot=
Due the progress in sensor electronics it was possible to design a autopilot with one planar PCB.
Compared to the HB-Autopilot V1.0 the following differences are given:
• use of new planar sensors: magnetsesor HMC5743, rate sensors LPR530AL LY530ALH or IDG500, IXZ500
• only one free 16Bit ADC input, and free 8 ADC Inputs with 10 bit, no intern difference pressure sensor, the 16Bit ADC is optional.
• dimensions 57mm*30mm* 11mm, cost: 26Euro for the 4 layer pcb, and 170 to 180 with all sensors. For normal plane aircrafts you can save about 60 Euro (no magnetsensor, no 16 Bit ADC, no pressure sensor)
This work was done by Benjamin Forke. You can get his bachelor thesis wirtten in German, if you wrote a question mail to paparazzi-devel at nongnu.org. The software implementation of the Paparazzi code for normal plane and quadrocopter is currently in work.

== Block Architecture ==
[[Image:Block.jpg]]
== Circuit Diagram page 1 ==
[[Image:HB_MINI_Strom1.jpg]]
== Circuit Diagram page 2 ==
[[Image:HB_MINI_Strom2.jpg]]

== Foto of Top side of PCB ==
[[Image:HB_Mini_Toppcb.jpg]]

== Foto of Bottom side of PCB ==
[[Image:HB_MINI_Bottompcb.jpg ]]

== HB-MINI-Autopilot on a Quadrocopter ==
[[Image:HB_MINI_Mount.jpg]]

== HB-MINI-Autopilot first Quadrocopter flight ==
[[Image:HB_MINI_Flight.jpg]]

[[Category:Hardware]] [[Category:Airframes]] [[Category:User_Projects]]

2010-12-24T16:00:47Z

Hwarm: /* HB-MINI-Autopilot on a Quadrocopter */

File:HB MINI Flight.jpg

2010-12-24T15:59:21Z

Hwarm: Prototype of HB-MINI-Autopilot on the first flight

Prototype of HB-MINI-Autopilot on the first flight

HB v1

2010-12-24T15:56:14Z

Hwarm: /* Foto of Bottom side of PCB */

File:HB MINI Mount.jpg

2010-12-24T15:52:31Z

Hwarm: Mounting on a Quadrocopter

Mounting on a Quadrocopter

2010-12-24T14:28:05Z

Hwarm: /* Circuit Diagram page 1 */

== HB_Autopilot Solutions ==

==HB-Autopilot V1.0==
The HB_Autopilot V1.0 hardware was built in Bremen based on Tiny 1.3 and Tiny 2.2 hardware.
It uses like booz a mcu and sensor pcb. The sensor pcb has same extensions to the booz pcb: temperature sensor pressure sensor with 24Bit ADC and difference pressure sensor. It can be used for a fixed wing aircraft or work with quadrocopters or helicopters.

'''Source:''' http://www.akaflieg.hs-bremen.de
'''Andreas Dei Report:''' http://www.akaflieg.hs-bremen.de/download/HB-Autopilot.pdf

== HB_Autopilot Images ==
<gallery>
Image:hb_ap01.jpg|PCB mockup
Image:hb_ap02.jpg|PCB mockup
Image:hb_ap03.jpg|Top HB_Autopilot
Image:hb_ap04.jpg|Bottom HB_Autopilot
</gallery>

== Detailed Images ==
<gallery>
Image:mcu_up.jpg|MCU Top
Image:mcu_down.jpg|MCU Bottom
Image:imu_up.jpg|IMU Top
Image:imu_down.jpg|IMU Bottom
Image:imu_sensors.jpg|IMU Sensors
</gallery>

== Block Architecture ==
[[Image:Block_Schematic.jpg]]

== Hardware Source Files==

Hardware- and software- files can be found here:
https://www.akaflieg.hs-bremen.de/trac/akaflieg/wiki/airborne/hw/autopilot

== Bill Of Material ==

For now you can see the BOM from Hardware Source Files.

== Authors ==

'''Team staff:'''
Heinrich Warmers hwarmers at hs-bremen.de
Oliver Riesener oliver.riesener at hs-bremen.de

'''Student work:'''
Andreas Dei andreas.dei at gmx.de
Thu Nguyen
Christoph Niemann
Henning Sauerland
Malte Lorbach
Arthur Neumann
Johannes Behn

'''Authors of external sources:'''
Killagreg
R O SoftWare
Michael Walter
Ralf Corsepius
KEIL ELEKTRONIK GmbH

==HB-MINI-planar Autopilot==
Due the progress in sensor electronics it was possible to design a autopilot with one planar PCB.
Compared to the HB-Autopilot V1.0 the following differences are given:
• use of new planar sensors: magnetsesor HMC5743, rate sensors LPR530AL LY530ALH or IDG500, IXZ500
• only one free 16Bit ADC input, and free 8 ADC Inputs with 10 bit, no intern difference pressure sensor, the 16Bit ADC is optional.
• dimensions 57mm*30mm* 11mm, cost: 26Euro for the 4 layer pcb, and 170 to 180 with all sensors. For normal plane aircrafts you can save about 60 Euro (no magnetsensor, no 16 Bit ADC, no pressure sensor)

== Block Architecture ==
[[Image:Block.jpg]]
== Circuit Diagram page 1 ==
[[Image:HB_MINI_Strom1.jpg]]
== Circuit Diagram page 2 ==
[[Image:HB_MINI_Strom2.jpg]]