PaparazziUAV - User contributions [en]

Module/GPS UBlox UCenter

2014-03-20T16:53:52Z

AndrewChambers: Added table describing the dynamics models

__TOC__
<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Modules</categorytree>
If you use a µ-blox GPS without flash memory, this module will take over the task of initializing the GPS for you when you power your autopilot.

It has auto-baudrate to detect the current GPS baudrate, and configures all message rates and communication ports. The module will send a DEBUG message (ID 26) that indicates the firmware version in your GPS, the previous baudrate, and the reply for each configuration step. To enable and view the message, you will need to define DEBUG_GPS_UBX_UCENTER as TRUE in your [[Airframe_Configuration|airframe configuration]] file and select to receive that message in your [[Telemetry|telemetry]] file. See the example below for more details.

It will configure the following settings:
* set baudrate to GPS_BAUD (typically either 38400 or 57600)
* enable the NAV_POSLLH, NAV_VELNED, NAV_STATUS, NAV_SVINFO, NAV_SOL
* disable UTM on old Lea4P by not sending NAV_POSUTM
* enable SBAS
* configure it to 3D only fix
* set the internal dynamic model to Airborne 2G

== Basic ==

Add the gps_ubx_ucenter [[Modules|module]] to the "modules" section in your aircraft configuration file:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml"/>
</modules>
</source>
}}

== Advanced ==

You can specify to a different dynamic model for the u-blox.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml">
<define name="GPS_UBX_NAV5_DYNAMICS" value="NAV5_DYN_PORTABLE" />
</load>
</modules>
</source>
}}

'''Additional details on GPS_UBX_NAV5_DYNAMICS'''

The ublox GPS uses a dynamics model (motion model) to filter the noisy GPS readings and produce smoother results. The dynamics
model will affect what positions and speeds are accurately tracked by GPS. Generally, it is recommend to use NAV5_DYN_PORTABLE for quadcopters and NAV5_DYN_AIRBORNE_2G for fixed wings.

The follow is taken from the ublox protocol specification document:

u-blox positioning technology supports different dynamic platform models to adjust the navigation engine to
the expected application environment. These platform settings can be changed dynamically without performing
a power cycle or reset. The settings improve the receiver's interpretation of the measurements and thus provide
a more accurate position output. Setting the receiver to an unsuitable platform model for the given application
environment results in a loss of receiver performance and position accuracy.

{| border="1"
|+ '''Dynamic Platform Model'''
|-
! scope="row" | NAV5_DYN_PORTABLE
| Applications with low acceleration, e.g. portable devices. Suitable for most situations. MAX Altitude [m]: 12000, MAX Velocity [m/s]: 310, MAX Vertical Velocity [m/s]: 50, Sanity check type: Altitude and Velocity, Max Position Deviation: Medium
|-
! scope="row" | NAV5_DYN_STATIONARY
| Used in timing applications (antenna must be stationary) or other stationary applications. Velocity restricted to 0 m/s. Zero dynamics assumed. MAX Altitude [m]: 9000, MAX Velocity [m/s]: 10, MAX Vertical Velocity [m/s]: 6, Sanity check type: Altitude and Velocity, Max Position Deviation: Small
|-
! scope="row" | NAV5_DYN_PEDESTRIAN
| Applications with low acceleration and speed, e.g. how a pedestrian would move. Low acceleration assumed. MAX Altitude [m]: 9000, MAX Velocity [m/s]: 30, MAX Vertical Velocity [m/s]: 20, Sanity check type: Altitude and Velocity, Max Position Deviation: Small
|-
! scope="row" | NAV5_DYN_AUTOMOTIVE
| Used for applications with equivalent dynamics to those of a passenger car. Low vertical acceleration assumed. MAX Altitude [m]: 6000 (5000 for firmware versions 6.00 and below), MAX Velocity [m/s]: 84 (62 for firmware versions 4.00 to 5.00), MAX Vertical Velocity [m/s]: 15, Sanity check type: Altitude and Velocity, Max Position Deviation: Medium
|-
! scope="row" | NAV5_DYN_SEA
| Recommended for applications at sea, with zero vertical velocity. Zero vertical velocity assumed. Sea level assumed. MAX Altitude [m]: 500, MAX Velocity [m/s]: 25, MAX Vertical Velocity [m/s]: 5, Sanity check type: Altitude and Velocity, Max Position Deviation: Medium
|-
! scope="row" | NAV5_DYN_AIRBORNE_1G
| Used for applications with a higher dynamic range and vertical acceleration than a passenger car. No 2D position fixes supported. MAX Altitude [m]: 50000, MAX Velocity [m/s]: 100, MAX Vertical Velocity [m/s]: 100, Sanity check type: Altitude, Max Position Deviation: Large
|-
! scope="row" | NAV5_DYN_AIRBORNE_2G
| Recommended for typical airborne environment. No 2D position fixes supported. MAX Altitude [m]: 50000, MAX Velocity [m/s]: 250, MAX Vertical Velocity [m/s]: 100, Sanity check type: Altitude, Max Position Deviation: Large
|-
! scope="row" | NAV5_DYN_AIRBORNE_4G
| Only recommended for extremely dynamic environments. No 2D position fixes supported. MAX Altitude [m]: 50000, MAX Velocity [m/s]: 500, MAX Vertical Velocity [m/s]: 100, Sanity check type: Altitude, Max Position Deviation: Large
|}

== Debug ==

You can specify to receive a DEBUG message over telemetry. Make changes to both the airframe and telemetry config files.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml">
<define name="GPS_UBX_NAV5_DYNAMICS" value="NAV5_DYN_PORTABLE" />
<define name="DEBUG_GPS_UBX_UCENTER" value="TRUE" />
</load>
</modules>
</source>
}}

{{Box Code|conf/telemetry/myplane.xml|
<source lang="xml">
<mode name="default">
...
<message name="DEBUG" period="0.5"/>
</mode>
</source>
}}

The debug messages has the following information:
* [0] Initial baudrate high
* [1] Initial baudrate low
* [2] ublox software verision high
* [3] ublox software version low
* [4] ublox hardware version high
* [5] ublox hardware version low
* [6] Always 0
* [7] Success of setting CFG-NAV5
* [8] Success of enable NAV-POSLLH
* [9] Success of enable NAV-VELNED
* [10] Success of enable NAV-STATUS
* [11] Success of enable NAV-SVINFO
* [12] Success of enable NAV-SOL
* [13] Success of disabling NAV-POSUTM (typically fails to 0 for non LEA-4P modules)
* [14] Success of enable SBAS
* [15] Success of setting CFG-RATE
* [16] Success of setting RXM-RAW (typically disabled - see USE_GPS_UBX_RXM_RAW flag to enable)
* [17] Success of setting RXM-SFRB (typically disabled - see USE_GPS_UBX_RXM_SFRB flag to enable)
* [18] Success of saving configuration to ublox memory

[[Category:User_Documentation]] [[Category:Modules]]

Module/GPS UBlox UCenter

2014-03-14T00:52:24Z

AndrewChambers: /* Debug */

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Modules</categorytree>
If you use a µ-blox GPS without flash memory, this module will take over the task of initializing the GPS for you when you power your autopilot.

It has auto-baudrate to detect the current GPS baudrate, and configures all message rates and communication ports. The module will send a DEBUG message (ID 26) that indicates the firmware version in your GPS, the previous baudrate, and the reply for each configuration step. To enable and view the message, you will need to define DEBUG_GPS_UBX_UCENTER as TRUE in your [[Airframe_Configuration|airframe configuration]] file and select to receive that message in your [[Telemetry|telemetry]] file. See the example below for more details.

It will configure the following settings:
* set baudrate to GPS_BAUD (typically either 38400 or 57600)
* enable the NAV_POSLLH, NAV_VELNED, NAV_STATUS, NAV_SVINFO, NAV_SOL
* disable UTM on old Lea4P by not sending NAV_POSUTM
* enable SBAS
* configure it to 3D only fix
* set the internal dynamic model to Airborne 2G

== Basic ==

Add the gps_ubx_ucenter [[Modules|module]] to the "modules" section in your aircraft configuration file:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml"/>
</modules>
</source>
}}

== Advanced ==

You can specify to a different dynamic model for the u-blox.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml">
<define name="GPS_UBX_NAV5_DYNAMICS" value="NAV5_DYN_PORTABLE" />
</load>
</modules>
</source>
}}

== Debug ==

You can specify to receive a DEBUG message over telemetry. Make changes to both the airframe and telemetry config files.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml">
<define name="GPS_UBX_NAV5_DYNAMICS" value="NAV5_DYN_PORTABLE" />
<define name="DEBUG_GPS_UBX_UCENTER" value="TRUE" />
</load>
</modules>
</source>
}}

{{Box Code|conf/telemetry/myplane.xml|
<source lang="xml">
<mode name="default">
...
<message name="DEBUG" period="0.5"/>
</mode>
</source>
}}

The debug messages has the following information:
* [0] Initial baudrate high
* [1] Initial baudrate low
* [2] ublox software verision high
* [3] ublox software version low
* [4] ublox hardware version high
* [5] ublox hardware version low
* [6] Always 0
* [7] Success of setting CFG-NAV5
* [8] Success of enable NAV-POSLLH
* [9] Success of enable NAV-VELNED
* [10] Success of enable NAV-STATUS
* [11] Success of enable NAV-SVINFO
* [12] Success of enable NAV-SOL
* [13] Success of disabling NAV-POSUTM (typically fails to 0 for non LEA-4P modules)
* [14] Success of enable SBAS
* [15] Success of setting CFG-RATE
* [16] Success of setting RXM-RAW (typically disabled - see USE_GPS_UBX_RXM_RAW flag to enable)
* [17] Success of setting RXM-SFRB (typically disabled - see USE_GPS_UBX_RXM_SFRB flag to enable)
* [18] Success of saving configuration to ublox memory

[[Category:User_Documentation]] [[Category:Modules]]

Module/GPS UBlox UCenter

2014-03-14T00:47:54Z

AndrewChambers: Description of the DEBUG message

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Modules</categorytree>
If you use a µ-blox GPS without flash memory, this module will take over the task of initializing the GPS for you when you power your autopilot.

It has auto-baudrate to detect the current GPS baudrate, and configures all message rates and communication ports. The module will send a DEBUG message (ID 26) that indicates the firmware version in your GPS, the previous baudrate, and the reply for each configuration step. To enable and view the message, you will need to define DEBUG_GPS_UBX_UCENTER as TRUE in your [[Airframe_Configuration|airframe configuration]] file and select to receive that message in your [[Telemetry|telemetry]] file. See the example below for more details.

It will configure the following settings:
* set baudrate to GPS_BAUD (typically either 38400 or 57600)
* enable the NAV_POSLLH, NAV_VELNED, NAV_STATUS, NAV_SVINFO, NAV_SOL
* disable UTM on old Lea4P by not sending NAV_POSUTM
* enable SBAS
* configure it to 3D only fix
* set the internal dynamic model to Airborne 2G

== Basic ==

Add the gps_ubx_ucenter [[Modules|module]] to the "modules" section in your aircraft configuration file:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml"/>
</modules>
</source>
}}

== Advanced ==

You can specify to a different dynamic model for the u-blox.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml">
<define name="GPS_UBX_NAV5_DYNAMICS" value="NAV5_DYN_PORTABLE" />
</load>
</modules>
</source>
}}

== Debug ==

You can specify to receive a DEBUG message over telemetry. Make changes to both the airframe and telemetry config files.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml">
<define name="GPS_UBX_NAV5_DYNAMICS" value="NAV5_DYN_PORTABLE" />
<define name="DEBUG_GPS_UBX_UCENTER" value="TRUE" />
</load>
</modules>
</source>
}}

{{Box Code|conf/telemetry/myplane.xml|
<source lang="xml">
<mode name="default">
...
<message name="DEBUG" period="0.5"/>
</mode>
</source>
}}

The debug messages has the following information:
* [0] Initial baudrate high
* [1] Initial baudrate low
* [2] ublox software verision high
* [3] ublox software version low
* [4] ublox hardware version high
* [5] ublox hardware version low
* [6] Success of setting CFG-NAV5
* [7] Success of enable NAV-POSLLH
* [8] Success of enable NAV-VELNED
* [9] Success of enable NAV-STATUS
* [10] Success of enable NAV-SVINFO
* [11] Success of enable NAV-SOL
* [12] Success of disabling NAV-POSUTM (typically fails to 0 for non LEA-4P modules)
* [13] Success of enable SBAS
* [14] Success of setting CFG-RATE
* [15] Success of setting RXM-RAW (typically disabled - see USE_GPS_UBX_RXM_RAW flag to enable)
* [16] Success of setting RXM-SFRB (typically disabled - see USE_GPS_UBX_RXM_SFRB flag to enable)
* [17] Success of saving configuration to ublox memory

[[Category:User_Documentation]] [[Category:Modules]]

Subsystem/ins

2014-03-06T17:03:20Z

AndrewChambers: /* no_type */

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages hideprefix=always>Subsystems</categorytree>
== INS subsystem ==
The INS (Inertial Navigation System) subsystem specifies which position and velocity estimation algorithm you are using.

Most of the INS filters are only providing position and speed, and they need to be used together with an AHRS filter for attitude. Currently, only the experimental invariant filter is a full INS.

Currently possible AHRS subsystem types are
* alt_float
* gps_passthrough
* xsens
* xsens700
* no_type
* hff
* extended
* ardrone2
* float_invariant

e.g. for the extended filter:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="ins" type="extended"/>
</firmware>
</source>
}}

== Implementations ==

=== alt_float ===
Filters altitude and climb rate for fixedwings.

A 2-state Kalman filter that estimates vertical position and vertical velocity from GPS and barometric data.

When USE_BAROMETER is true:
* GPS horizontal position and horizontal velocity is directly passed through
* GPS vertical position sets the altitude for the barometric reference pressure (QFE)
* Vertical position and velocity is a filtered based on barometric pressure with respect to the reference pressure and GPS vertical velocity readings.

When USE_BAROMETER is false or undefined:
* GPS velocity is directly passed through to the vehicle's state.
* GPS horizontal position is directly passed through.
* Altitude is filtered based on GPS height and vertical velocity data.

'''Parameters'''

USE_BAROMETER - Enables the use of barometric data

DEBUG_ALT_KALMAN - Enables debug messages from the subsystem (Default: not defined)

=== GPS passthrough (gps_passthrough) ===

=== xsens ===
XSens Mti-G

<source lang="xml">
<subsystem name="ins" type="xsens">
<configure name="XSENS_UART_NR" value="0"/>
<configure name="XSENS_UART_BAUD" value="B115200"/>
</subsystem>
</source>

=== xsend700 ===
XSens Mti-G

<source lang="xml">
<load name="ins_xsens_MTiG_fixedwing.xml">
<configure name="XSENS_UART_NR" value="0"/>
</load>
</source>

=== no_type ===
Vertical filter (in float) estimating altitude, vertical velocity and accelerometer bias.

If USE_GPS, horizontal position and velocity is set directly by GPS.

<source lang="xml">
<subsystem name="ins"/>
</source>

=== Horizontal Filter Float (hff) ===
simple with float vertical and horizontal filters for INS

=== extended ===
Extended vertical filter (in float).

A 4-state Kalman filter that estimates:
* vertical position
* vertical speed
* accelerometer bias
* barometric offset

'''Parameters'''

INS_PROPAGATE_FREQUENCY - Defines the frequency (Hz) of the propagation model (Default: PERIODIC_FREQUENCY)

=== ardrone2 ===
simple INS with float vertical filter for use with ardrone2_sdk

=== float_invariant ===
attitude and speed estimation for fixedwings via invariant filter

[[Category:User_Documentation]] [[Category:Subsystems]]

Subsystem/ins

2014-03-06T16:42:36Z

AndrewChambers: /* extended */

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages hideprefix=always>Subsystems</categorytree>
== INS subsystem ==
The INS (Inertial Navigation System) subsystem specifies which position and velocity estimation algorithm you are using.

Most of the INS filters are only providing position and speed, and they need to be used together with an AHRS filter for attitude. Currently, only the experimental invariant filter is a full INS.

Currently possible AHRS subsystem types are
* alt_float
* gps_passthrough
* xsens
* xsens700
* no_type
* hff
* extended
* ardrone2
* float_invariant

e.g. for the extended filter:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="ins" type="extended"/>
</firmware>
</source>
}}

== Implementations ==

=== alt_float ===
Filters altitude and climb rate for fixedwings.

A 2-state Kalman filter that estimates vertical position and vertical velocity from GPS and barometric data.

When USE_BAROMETER is true:
* GPS horizontal position and horizontal velocity is directly passed through
* GPS vertical position sets the altitude for the barometric reference pressure (QFE)
* Vertical position and velocity is a filtered based on barometric pressure with respect to the reference pressure and GPS vertical velocity readings.

When USE_BAROMETER is false or undefined:
* GPS velocity is directly passed through to the vehicle's state.
* GPS horizontal position is directly passed through.
* Altitude is filtered based on GPS height and vertical velocity data.

'''Parameters'''

USE_BAROMETER - Enables the use of barometric data

DEBUG_ALT_KALMAN - Enables debug messages from the subsystem (Default: not defined)

=== GPS passthrough (gps_passthrough) ===

=== xsens ===
XSens Mti-G

<source lang="xml">
<subsystem name="ins" type="xsens">
<configure name="XSENS_UART_NR" value="0"/>
<configure name="XSENS_UART_BAUD" value="B115200"/>
</subsystem>
</source>

=== xsend700 ===
XSens Mti-G

<source lang="xml">
<load name="ins_xsens_MTiG_fixedwing.xml">
<configure name="XSENS_UART_NR" value="0"/>
</load>
</source>

=== no_type ===
simple INS with float vertical filter

<source lang="xml">
<subsystem name="ins"/>
</source>

=== Horizontal Filter Float (hff) ===
simple with float vertical and horizontal filters for INS

=== extended ===
Extended vertical filter (in float).

A 4-state Kalman filter that estimates:
* vertical position
* vertical speed
* accelerometer bias
* barometric offset

'''Parameters'''

INS_PROPAGATE_FREQUENCY - Defines the frequency (Hz) of the propagation model (Default: PERIODIC_FREQUENCY)

=== ardrone2 ===
simple INS with float vertical filter for use with ardrone2_sdk

=== float_invariant ===
attitude and speed estimation for fixedwings via invariant filter

[[Category:User_Documentation]] [[Category:Subsystems]]

Subsystem/ins

2014-03-05T23:51:39Z

AndrewChambers: /* ardrone2 */

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages hideprefix=always>Subsystems</categorytree>
== INS subsystem ==
The INS (Inertial Navigation System) subsystem specifies which position and velocity estimation algorithm you are using.

Most of the INS filters are only providing position and speed, and they need to be used together with an AHRS filter for attitude. Currently, only the experimental invariant filter is a full INS.

Currently possible AHRS subsystem types are
* alt_float
* gps_passthrough
* xsens
* xsens700
* no_type
* hff
* extended
* ardrone2
* float_invariant

e.g. for the extended filter:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="ins" type="extended"/>
</firmware>
</source>
}}

== Implementations ==

=== alt_float ===
Filters altitude and climb rate for fixedwings.

A 2-state Kalman filter that estimates vertical position and vertical velocity from GPS and barometric data.

When USE_BAROMETER is true:
* GPS horizontal position and horizontal velocity is directly passed through
* GPS vertical position sets the altitude for the barometric reference pressure (QFE)
* Vertical position and velocity is a filtered based on barometric pressure with respect to the reference pressure and GPS vertical velocity readings.

When USE_BAROMETER is false or undefined:
* GPS velocity is directly passed through to the vehicle's state.
* GPS horizontal position is directly passed through.
* Altitude is filtered based on GPS height and vertical velocity data.

'''Parameters'''

USE_BAROMETER - Enables the use of barometric data

DEBUG_ALT_KALMAN - Enables debug messages from the subsystem (Default: not defined)

=== GPS passthrough (gps_passthrough) ===

=== xsens ===
XSens Mti-G

<source lang="xml">
<subsystem name="ins" type="xsens">
<configure name="XSENS_UART_NR" value="0"/>
<configure name="XSENS_UART_BAUD" value="B115200"/>
</subsystem>
</source>

=== xsend700 ===
XSens Mti-G

<source lang="xml">
<load name="ins_xsens_MTiG_fixedwing.xml">
<configure name="XSENS_UART_NR" value="0"/>
</load>
</source>

=== no_type ===
simple INS with float vertical filter

<source lang="xml">
<subsystem name="ins"/>
</source>

=== Horizontal Filter Float (hff) ===
simple with float vertical and horizontal filters for INS

=== extended ===
extended INS with vertical filter using sonar in a better way (flap ground)

=== ardrone2 ===
simple INS with float vertical filter for use with ardrone2_sdk

=== float_invariant ===
attitude and speed estimation for fixedwings via invariant filter

[[Category:User_Documentation]] [[Category:Subsystems]]

Modems

2014-03-05T20:01:31Z

AndrewChambers: Link to Digi's Government Certification Page

The Paparazzi autopilots generally feature a TTL serial port to interface with any common radio modem. The bidirectional link provides real-time telemetry and in-flight tuning and navigation commands. The system is also capable overlaying the appropriate protocols to communicate thru non-transparent devices such as the Coronis Wavecard or Maxstream API-enabled products, allowing for hardware addressing for multiple aircraft or future enhancements such as data-relaying, inter-aircraft communication, RSSI signal monitoring and automatic in-flight modem power adjustment. Below is a list of some of the common modems used with Paparazzi, for details on configuring your modem see the [[Airframe_Configuration#Telemetry_.28Modem.29|Airframe Configuration]] and [[XBee_configuration|XBee Configuration]] pages.

==General comparison==
'''This is ONLY a comparison between modules which work acceptably'''

All modules listed here work without issue and are generally available.
{| border="1" cellspacing="0" style="text-align:center" cellpadding="2%"
| align="center" style="background:#f0f0f0;"|'''Feature'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_DigiMesh_.2F_802.15.4_.28.22Series_1.22.29|XBee Series 1]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_DigiMesh_.2F_802.15.4_.28.22Series_1.22.29|XBee Pro Series 1]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_ZB_.2F_ZNet_2.5_.28.22Series_2.22.29|XBee Series 2]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_ZB_.2F_ZNet_2.5_.28.22Series_2.22.29|XBee Pro Series 2]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_868LP|XBee 868LP]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_900HP|XBee Pro 900HP]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_XSC_900MHz|XBee Pro XSC 900]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_9XTend|Digi 9XTend]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#SiLabs_Si1000_SoC_based_modems|SiLabs Si1000]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#AC4790-200|Aerocom AC4790-200]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#AC4790-1000|Aerocom AC4790-1000]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Laird_RM024|Laird RM024 50mW]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Laird_RM024|Laird RM024 125mW]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#RN-41_Bluetooth_module.28Sparkfun.27s_WRL-08497.29|RN-41 Bluetooth]]'''
|-
| style="background:#f0f0f0;"|'''frequency'''||2,4GHz||2,4GHz||2,4GHz||2,4GHz||868MHz||900MHz||900MHz||900MHz, 2.4GHz||240-960MHz||900MHz||900MHz||2,4GHz||2,4GHz||2,4GHz
|-
| style="background:#f0f0f0;"|'''output power'''||1mW||63mW (US) 10 mW (Int'l)||2mW||63mW||5mW||250mW||250mW||1mW-1W||max 100mW||5-200mW||5-1000mW||2,5-50mW||2,5-125mW||32mW
|-
| style="background:#f0f0f0;"|'''RF speed'''||250kbps||250kbps||250kbps||250kbps||10kbps, 80kbps||10 or 200kbps||10, 20kbps||9.6, 115.2kbps|| ||76.8kbps||76.8kbps||280, 500kbps||280, 500kbps||300kbps
|-
| style="background:#f0f0f0;"|'''antenna'''||chip, wire, rpsma, u.fl||chip, wire, rpsma, u.fl||chip, wire, rpsma, u.fl||chip, wire, rpsma, u.fl||external required||wire, rpsma, u.fl||wire, rpsma, u.fl||rpsma, MMCX||external required||MMCX, internal Antenna||MMCX||u.fl, chip, both||u.fl, chip, both||pcb trace
|-
| style="background:#f0f0f0;"|'''pinout'''||XBee||XBee||XBee||XBee||SMD||XBee||XBee||20 pin 2,54mm/USB||SMD (42 pin LGA)||20 pin mini connector||20 pin mini connector||XBee/SMD||XBee/SMD||SMD
|-
| style="background:#f0f0f0;"|'''price'''||16€||26€||14€||28€||18€||32€||32€||150€||4€||52€||64€||30€||30€||20€
|-
| style="background:#f0f0f0;"|'''for Country'''||Worldwide||Worldwide||Worldwide||Worldwide||Europe||North America, Australia||North America, Australia||Worldwide||Worldwide||North America, Australia||North America, Australia||Europe||North America||Worldwide
|}

==Frequencies==

Analog and digital (video and modem) can NOT be done over the same frequency !!!

You may want to inform yourself about your countries laws ! Different countries allow different frequencies at different power. 
Sending on a wrong frequency or with too much power may end in a serious lawsuit !

Digi: [http://www.digi.com/technology/rfmodems/agencyapprovals Government Agency Certifications]

== Digi XBee modules ==

Digi (formerly Maxstream) offers an increasing variety of Zigbee protocol modems well suited for Paparazzi in 2.4 GHz, 900MHz and 868Mhz frequencies. The "Pro" series are long range, up to 40km! Standard series are slightly smaller/lighter/lower power consumption and very short range. All versions are all pin compatible and weigh around 2 grams with wire antennas. All Digi modems can be operated in transparent mode (as a serial line replacement) or in "API mode" with hardware addressing, managed networking, and RSSI (signal strength) data with the Paparazzi "Xbee" option.

Four antenna options are offered: RP-SMA, U-FL, wire antenna, chip antenna

* XBee (PRO) ZB (the current series)
* XBee (PRO) ZNet 2.5 (formerly Series 2) (only legacy -> use XBee-PRO ZB)
The XBee & XBee-PRO ZB share hardware (ember stack) with XBee & XBee-PRO ZNet 2.5. As a result, modules can be "converted" from one platform to another by loading different firmware onto a given module.

These two also share the same hardware and can be converted from one to another by flashing a different firmware:
* XBee-PRO 802.15.4 (formerly Series 1)
* XBee-PRO DigiMesh 2.4

'''Note: Modules based on Freescale chipset (formerly Series 1) are not compatible with Ember chipset based modules (Series 2).'''

If only point to point or point to multipoint communication is required 802.15.4 will do the job. These are designed for high data rates and low latency. 
Modules with Zigbee firmware are needed for mesh functionality(communication between the UAV's)

See the [[XBee_configuration|XBee Configuration]] page. This [http://pixhawk.ethz.ch/tutorials/how_to_configure_xbee tutorial] is also good to configure and get started with XBee Pro.

=== Module Comparison ===
{|border="1"
|-valign="top"
||'''Module'''||'''Point-to-Multipoint'''||'''ZigBee/Mesh'''||'''Chipset'''|||'''Software stack'''||'''Frequency'''||'''TX Power normal/PRO'''||'''Notes'''
|-
|'''XBee ZB'''
|
|yes
|Ember
|EmberZNet PRO 3.1 (ZigBee 2007)
|2.4 GHz
|2mW/50mW
|coordinator needed
|-
|'''XBee ZNet 2.5'''
|
|yes
|Ember
|EmberZNet 2.5 ZigBee
|2.4 GHz
|2mW/50mW
|(only legacy -> use XBee-PRO ZB) coordinator needed
|-
|'''XBee DigiMesh 2.4'''
|
|yes
|Freescale
|
|2.4 GHz
|
|all nodes equal (no special coordinators/routers/end-devices)
|-
|'''XBee 802.15.4'''
|yes
|
|Freescale
|
|2.4 GHz
|
|
|-
|'''XBee-PRO 868'''
|yes
|
|?
|
|868 MHz
|500mW
|Only High Power Frequency allowed in the UK. 2.4GHz limited to 10mW
|}

==== Pinout ====

[[Image:Maxstream_Xbee_pinout.jpg|left|thumb|Maxstream XBee pinout]]
 

{|border="1"
|-valign="top"
||''Xbee 20-pin Header''||''Name''||''Notes''||''Suggested Color''||
|-
|1
| +3.3v
| Power
|Red
|-
|2
|DOUT
|Tx output - connect to Autopilot Rx
|Green
|-
|3
|DIN
|Rx input - connect to Autopilot Tx
|Blue
|-
|10
|GND
| Ground
|Black
|}

The image view is from above, top, thus NOT at the side where the connector pins come out

Note : DTR and RTS need to be wired for upgrading firmware

=== GCS Adaptation ===

There are several vendors of hardware to connect the ground XBee radio modem to the GCS computer.

====Adafruit====

[[Image:xbeeadapter_LRG.jpg|thumb|left|Adafruit XBee adapter board]][[Image:xbeeadapterftdi_LRG.jpg|thumb|Adafruit XBee adapter with FTDI cable]]
[http://www.adafruit.com/index.php?main_page=product_info&cPath=29&products_id=126 Adafruit] offers a great adapter board kit for the Xbee modules that includes a 5-3.3V voltage regulator, power and activity LEDs, and pins to connect directly to your FTDI cable for $10! Some assembly required.

 

====Droids====

[[Image:XBee_Simple_Board.jpg|thumb|left|XBee Simple Board]]

[[Image:XBee_USB_Board.jpg|thumb|left|XBee USB Board]]

[http://www.droids.it/cmsvb4/content.php?143-990.001-XBee-Simple-Board XBee Simple Board]

Simpler, lighter, smaller footprint, bit more expensive, comes assembled and tested. --GR

[http://www.droids.it/cmsvb4/content.php?152-990.002-XBee-USB-Board XBee USB Board]

For direct connection to USB (no FTDI cable required)

 

====PPZUAV====

[[Image:FTDI_Utility_Board.jpg|thumb|left|FTDI Utility Board 1.0‎]]

[https://www.ppzuav.com/osc/product_info.php?cPath=13&products_id=111&osCsid=upcl59vp10vdvno35ejl453442 ppzuav.com product link]

FTDI Utility Board 1.0 with FTDI232RL 
On board XBEE connector and molex picoblade connectors.

 

====Sparkfun====

[[Image:XBee_Explorer_USB.jpg|thumb|left|XBee Explorer USB]]

[http://www.sparkfun.com/products/8687 sparkfun.com]

XBee Explorer USB with FTDI232RL

 

=== Digi XBee Pro DigiMesh / 802.15.4 ("Series 1") ===
*Note: Products based on XBee ZNet 2.5 (formerly Series 2) modules do not communicate with products based on XBee DigiMesh / 802.15.4 (formerly Series 1) modules.

These relatively cheap and light modules implement the [http://www.zigbee.org/en/index.asp ZigBee/IEEE 802.15.4] norm. They allow up to 1.6km (1 mile) range (Paparazzi tested to 2.5km (1.5 miles)). The main drawback of using such 2.4Ghz modules for datalink is that it will interfere with the 2.4Ghz analog video transmitters and a inevitable decrease in range when in proximity to any wifi devices. For the plane, get the whip antenna version if you are not planning to build a custom antenna.

{|
|-valign="top"
|[[Image:Xbee_Pro_USB_RF_Modem.jpg|thumb|left|XBee Pro USB Stand-alone Modem (XBP24-PKC-001-UA)]]
|
* Frequency Band 2.4GHz
* Output Power 100mW (Xbee Pro)
* Sensitivity -100 dBm
* RF Data Rate Up to 250 Kbps
* Interface data rate Up to 115.2 Kbps
* Power Draw (typical) 214 mA TX / 55 mA RX
* Supply Voltage 3.3v
* Range (typical, depends on antenna & environment) Up to 1500m line-of-sight
* Dimensions 24 x 33mm
* Weight 4 grams
* Interface 20-pin mini connector
* Chip antenna, ¼ monopole integrated whip antenna or a U.FL antenna connector (3 versions)
* Price: 16€, Pro 26€
|
[[Image:XBee_pro.jpg|thumb|left|XBee Pro OEM Modem]]
|}
Mouser: [http://au.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMtJacPDJcUJYzVn8vIv7g2fIpf5DCzJqko%3d 888-XBP24-PKC-001-UA] 
NOTE: If you wish to use this unit with another XBee type other than the 802.15.4 (i.e. XBee-PRO ZB) then purchase a modem with the U.fl connector.

==== Documentation ====

* [http://www.maxstream.net/products/xbee/xbee-pro-oem-rf-module-zigbee.php product page]
* [http://www.maxstream.net/products/xbee/datasheet_XBee_OEM_RF-Modules.pdf datasheet]
* [http://www.maxstream.net/products/xbee/product-manual_XBee_OEM_RF-Modules.pdf user manual]
* To program your Xbee you need X-CTU you can download it [http://www.digi.com/support/productdetl.jsp?pid=3352&osvid=57&tp=5&s=316 here]. (only windows)
* explanation on X-CTU [http://www.ladyada.net/make/xbee/configure.html here].
* [http://ftp1.digi.com/support/firmware/update/xbee/ Drivers for XB24 and XBP24 modules]

=== Digi XBee Pro ZB / ZNet 2.5 ("Series 2") ===

The low-power XBee ZB and extended-range XBee-PRO ZB use the ZigBee PRO Feature Set for advanced mesh networking.

{|
|-valign="top"
|[[Image:XBee_Pro_2SB.jpg|thumb|left|Digi XBee Pro ZB]]
|
* Low-cost, low-power mesh networking
* Interoperability with ZigBee PRO Feature Set devices from other vendors*
* Support for larger, more dense mesh networks
* 128-bit AES encryption
* Frequency agility
* Over-the-air firmware updates (change firmware remotely)
* ISM 2.4 GHz operating frequency
* XBee: 2 mW (+3 dBm) power output (up to 400 ft RF LOS range)
* XBee-PRO: 50 mW (+17 dBm) power output (up to 1 mile RF LOS range)
* RPSMA connector, U.FL connector, Chip antenna, or Wired Whip antenna
* price : 14€, Pro 28€
|
|}
These are available from Mouser: 
[http://au.mouser.com/Search/Refine.aspx?Keyword=888-XBP24-Z7WIT-004 888-XBP24-Z7WIT-004] XBee-PRO ZB with whip antenna 
[http://au.mouser.com/Search/Refine.aspx?Keyword=XBP24-Z7SIT-004 888-XBP24-Z7SIT-004] XBee-PRO ZB with RPSMA

See [[XBee_configuration|XBee Configuration]] for setup.

==== Documentation ====
* [http://www.digi.com/products/wireless/zigbee-mesh/xbee-zb-module.jsp http://www.digi.com/products/wireless/zigbee-mesh/xbee-zb-module.jsp]

=== Digi XBee Pro 868 ===

'''WARNING - THESE MODEMS HAVE A 10% DUTY CYCLE, AND CURRENTLY HAVE SEVERE ISSUES WITH PAPARAZZI'''

868MHz is a limited band. Please read the [[868MHz Issues]]

XBee-PRO 868 modules are long range embedded RF modules for European applications. Purpose-built for exceptional RF performance, XBee-PRO 868 modules are ideal for applications with challenging RF environments, such as urban deployments, or where devices are several kilometers apart.

{|
|-valign="top"
|[[Image:xbeeproxsc-rpsma.jpg|thumb|left|Maxstream XBee Pro 868]]
|
* 868 MHz short range device (SRD) G3 band for Europe
* Software selectable Transmit Power
* 40 km RF LOS w/ dipole antennas
* 80 km RF LOS w/ high gain antennas (TX Power reduced)
* Simple to use peer-to-peer/point-to-mulitpoint topology
* 128-bit AES encryption
* 500 mW EIRP
* 24 kbps RF data rate
* price : ~70 USD
|
|}

See [[XBee_configuration#XBee_Pro_868_MHZ|XBee Configuration]] for setup.

==== Documentation ====
* [http://www.digi.com/products/wireless/point-multipoint/xbee-pro-868.jsp http://www.digi.com/products/wireless/point-multipoint/xbee-pro-868.jsp]

=== Digi XBee 868LP ===

XBee 868LP modules are a low-power 868 MHz RF module for use in Europe. The range is shorter than it's brother the XBee PRO-868, but it can use the 868 G4 band with hopping which does not have restrictions on it's duty cycle. This is a big advantage if one want to have a good stream of telemetry data

{|
|-valign="top"
|[[Image:868lp.jpg|thumb|left|XBee 868LP]]
|
* 868 MHz short range device (SRD) G4 band for Europe
* 4 km RF LOS w/ u.fl antennas
* 5 mW EIRP
* 10 or 80 kbps RF data rate
* price : 18€
|
|}

==== Documentation ====
* [http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/zigbee-mesh-module/xbee-868lp#overview http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/zigbee-mesh-module/xbee-868lp#overview]

==== Trial ====

With a quickly crafted and not optimal positioned antenna on the airframe we managed to get the advertised 4000 meter range. Data throughput was not high and the Iridium Telemetry XML configuration document was therefore used. All in all, cheap, easy to setup, pin compatible with regular modules and quite a range and usable in Europe without hassle.

=== Digi XBee Pro 900HP ===
* Frequency band 900Mhz
* RF rate 10 or 200 kbps
* up to 250mW output power
* 5 to 8 gramm
* price: 32€

==== Documentation ====
[http://ftp1.digi.com/support/documentation/90002173_H.pdf http://ftp1.digi.com/support/documentation/90002173_H.pdf]

=== Digi XBee Pro XSC 900MHz ===

Maxstream has recently announced a promising new line of modems combining the small size and low cost of their popular Xbee line with the long range and 2.4 GHz video compatibility of their high end 900 MHz models. Sounds like the perfect modem for anyone who can use 900 MHz. Give them a try and post your results here!
{|
|-valign="top"
|[[Image:xbeeproxsc-rpsma.jpg|thumb|left|Maxstream XBee Pro XSC]]
|
* Frequency Band 900 MHz
* Output Power 100 mW (+20 dBm)
* Sensitivity -100 dBm
* RF Rate: 10 or 20 kbps
* Range (typical, depends on antenna & environment) Up to 24km (15 miles) line-of-sight
* Interface 20-pin mini connector (Xbee compatible pinout)
* RPSMA, integrated whip antenna or U.FL antenna connector (3 versions)
* price : 32€
|
|}

==== Documentation ====
* [http://www.digi.com/products/wireless/point-multipoint/xbee-pro-xsc.jsp http://www.digi.com/products/wireless/point-multipoint/xbee-pro-xsc.jsp]

==== Trials ====
Tested one today and it worked great. Going to try a multiUAV test with it soon
--Danstah
 
 
MultiUAV tests concluded this is probably not the best module to use. Even though it says you can change the baudrate inside x-ctu that is not the case, it is fixed at 9600 bps. This is a great modem however for single UAV's and I do recommend.
--Danstah
 
 
Why would the European (868 MHz) be good to 24kbps and this only to 9600? When I was altering my XBees (2.4Ghz Pro's) I had this problem altering baud rates until I read you have to send a "commit and reboot" type command after setting the baud rate. Could this be the case? --GR

=== Digi 9XTend ===

These larger units have been tested on the 900Mhz band, but are also available in 2.4Ghz. They are a bit on the heavy side, about 20 grams, but give good performance at range. They have adjustable transmit power settings from 100mW to 1W. Testing has shown range up to 5.6km (3.5 Miles) with XTend set to 100mW with small 3.1dB dipole antenna.

{|
|-valign="top"
|
[[Image:XTend_USB_RF_Modem.jpg|frame|left|9XTend USB Modem]]
|
* Frequency Band 900Mhz and 2.4Ghz (2 versions)
* Output Power 1mW to 1W software selectable
* Sensitivity -110 dBm (@ 9600 bps)
* RF Data Rate 9.6 or 115.2 Kbps
* Interface data rate up to 230.4 Kbps
* Power Draw (typical) 730 mA TX / 80 mA RX
* Supply Voltage 2.8 to 5.5v
* Range (typical, depends on antenna & environment) Up to 64km line-of-sight
* Dimensions 36 x 60 x 5mm
* Weight 18 grams
* Interface 20-pin mini connector or USB
* RF connector RPSMA (Reverse-polarity SMA) or MMCX (2 versions)
* price : 150€
|
[[Image:Xtend_module.jpg|frame|left|9XTend OEM Modem]]
|}

==== Pinout ====

[[Image:Maxstream_9XTend_Pinout.gif|thumb|left|Maxstream 9XTend Pinout]]

{| border="1"
|-valign="top"
||'''''9XTend 20-pin Header'''''||'''''Name'''''||'''''Tiny Serial-1 Header'''''||'''''Notes'''''
|-
||1||GND||1 (GND)||Ground
|-
||2||VCC||2 (5V)||5V power (150mA - 730mA Supplied from servo bus or other 5V source)
|-
||5||RX||8 (TX)||3-5V TTL data input - connect to Tiny TX
|-
||6||TX||7 (RX)||5V TTL data output - connect to Tiny RX
|-
||7||Shutdown||2||This pin must be connected to the 5V bus for normal operation
|}
Notes: 
* 9XTend can run on voltages as low as 2.8V but users are strongly advised against connecting any modem (especially high power models) to the sensitive 3.3V bus supplying the autopilot processor and sensors.
 

==== Documentation ====

* [http://www.maxstream.net/products/xtend/oem-rf-module.php product page]
* [http://www.maxstream.net/products/xtend/datasheet_XTend_OEM_RF-Module.pdf datasheet]
* [http://www.maxstream.net/products/xtend/product-manual_XTend_OEM_RF-Module.pdf user manual]

==== Configuration ====

These modems need to be carefully configured based on your usage scenario to obtain the best possible range and link quality. In addition, it is always good to make sure the firmware is up to date.

Some typical configurations that may work well, but can still depend your particular situation, are given below. For further details, be sure to consult the XTend users manual. Your application may need a different or modified configuration. The radiomodems do not need identical settings and can in fact be optimized with different settings. A good example is delays and retries: if each radio has the same number of retries and no delay, when a collision occurs each will continuously try to re-transmit, locking up the transmission for some time with no resolution or successful packet delivery. Instead, it is best to set the module whose data should have a lower latency to have no delay and a lower number of retries, while the other module has a delay set (RN > 0) and a greater number of retries. See acknowledged mode example below.

* Acknowledged Polling Mode ('''Recommended'''):
** This causes one radio to be the base and the other(s) to be the remote(s). It eliminates collisions because remotes do not send data unless requested by the base. It can work in acknowledged mode (RR>0), basic reliable mode (MT>0) or in basic mode (no acknowledgement or multiple packets). It is recommended that the lower latency and/or higher data rate side be configured as the base (i.e. if you are sending lots of telemetry then the air module configured as the base is probably a good idea, but if you are using datalink joystick control, the ground side might be better as the base. It may require some experimentation).
* Acknowledged Point-to-(Multi)Point Mode:
** Each radio sends a packet and requests and acknowledgement that the packet was sent from the receiving side. The retries and delays must be set appropriately to ensure packet collisions are dealt with appropriately. It can also work without acknowledgements in basic reliable mode (MT>0) without any acknowledgements (RR=0, MT=0). Some experimentation may be required.

{| border="1"
|-valign="top"
||'''''Setting Name'''''||colspan="2"|'''''Acknowledged Mode'''''||colspan="2"|'''''Polling Mode (Acknowledged)'''''||'''''Notes'''''
|-
|| ||'''''Airside Module'''''||'''''Groundside Module'''''||'''''Base Module'''''||'''''Remote Module'''''||
|-
||BD||6||6||6||6||Adjust to match your configured autopilot and ground station baud rates (default for these is 57600bps)
|-
||DT||default||default||0x02||0x01||Can be adjusted if consistency maintained across addressing functionalities (see manual)
|-
||MD||default||default||3 (0x03)||4 (0x04)||
|-
||MT||0||0||0||0||Use this to enable Basic Reliable transmission, link bandwidth requirement increases (see manual)
|-
||MY||default||default||0x01||0x02||Can be adjusted if consistency maintained across addressing functionalities (see manual)
|-
||PB||default||default||0x02||default||Can be adjusted if consistency maintained across addressing functionalities (see manual)
|-
||PD||default||default||default||default||Can be adjusted to increase polling request rate and DI buffer flush timeout (see manual)
|-
||PE||default||default||0x02||default||Can be adjusted if consistency maintained across addressing functionalities (see manual)
|-
||PL||default||default||default||default||''Transmit power level should be reduced for lab testing!!''
|-
||RN||0 (0x00)||8 (0x08)||default||default||
|-
||RR||6 (0x06)||12 (0x0C)||6 (0x06)||12 (0x0C)||
|}

'''Note:''' All settings are assumed to be default except those listed. Those listed are in decimal unless hex 0x prefix included. Depending on your firmware version, slight modifications may be necessary.

Here is some additional information and alternative instructions to configure the polling mode from the Digi site: [http://www.digi.com/support/kbase/kbaseresultdetl?id=2178 Polling Mode for the 9XTend Radio Modem]

== SiLabs Si1000 SoC based modems ==

The Si1000 radio System on Chip (SOC) produced by SiLabs is found in a number of radio modules, for example the cheap and widely used HopeRf module. There is [https://github.com/tridge/SiK open source firmware] for these radios which makes them suitable for use in MAVs.

Note that (unlike some XBee modules) the SiK firmware does not support mesh topologies, it is strictly a point-to-point link. If you are working with swarming vehicles they may not be the best choice.

Online documentation for the Sik firmware shows how to configure it for various jurisdictions. The firmware supports 433 MHz, 470 MHz, 868 MHz and 900 MHz radios, if you are aware of any hardware supporting the European spectrum licences (868 MHz) please add them to this wiki.

Note: When using a SiK firmware radio with paparazzi, you should set "ATS6=0" (MavLink packing off) and configure paparazzi for transparent serial mode.

[http://www.rfdesign.com.au/index.php/rfd900 This module] is well proven and supports antenna diversity. A combination of 6dbi Yagi plus a dipole on the ground station, with a pair of orthogonality oriented dioples in the airframe, has been extensively tested and proven reliable at >8km range (theoretical range of ~40km).

Alternatively, for shorter range a pair of cheap generic HopeRF-based modems [http://rctimer.com/index.php?gOo=goods_details.dwt&goodsid=815 such as these]

The RFD900 can be paired with cheap generic (single front-end) modules, if for example you use a small short range airframe with a ground station that's also used for long range operations.

== Laird (ex Aerocom) ==
Lairds's API mode is already implemented but some system integration is required. Full API more with addressed packets works well and was tested with AC4790-1x1 5mW low power modules. Maximim range achieved with a whip quater-wave antenna was 1Km.

How to use this modem on ground station side? [http://paparazzi.enac.fr/wiki/index.php/User:SilaS#SDK-AC4868-250_ground_modem_part]

See folder paparazzi3 / trunk / sw / aerocomm. It has all the required files to use this modem on the airborne and ground station side. The link.ml file is a direct replacement of the "main" link.ml file of the ground sttaion and will be merged into it in the future.. or you can do it as well.

{|
|
=== AC4790-200 ===
* Frequency 902-928MHz (North America, Australia, etc).
* Output Power 5-200mW
* Sensitivity (@ full RF data rate) -110dB
* RF Data Rate up to 76.8 Kbps
* INterface Data Rate Up to Up to 115.2 Kbps
* Power Draw (typical) 68 mA
* Supply Voltage 3.3v & 5.5V
* Range (typical, depends on antenna & environment) Up to 6.4 kilometers line-of-sight
* Dimensions 42 x 48 x 5mm
* Weight < 20 grams
* Interface 20-pin mini connector
* Antenna MMCX jack Connector or internal
* price : 52€
|
[[Image:ac4868_transceiver.jpg|thumb|left|AC4868 OEM Modem]]
|
|-
|
=== AC4790-1000 ===
* Frequency 902-928MHz (North America, Australia, etc).
* Output Power 5-1000mW
* Sensitivity (@ full RF data rate) -99dB
* RF Data Rate up to 76.8 Kbps
* INterface Data Rate Up to Up to 115.2 Kbps
* Power Draw (typical) 650 mA
* Supply Voltage 3.3V only
* Range (typical, depends on antenna & environment) Up to 32 kilometers with high-gain antenna
* Dimensions 42 x 48 x 5mm
* Weight < 20 grams
* Interface 20-pin mini connector
* Antenna MMCX jack Connector
* price : 64€
|}

=== Pinout ===

[[Image:Aerocomm_AC4868_pinout.jpg|thumb|left|Laird AC4868 modem pinout]]
[[Image:Aerocomm_AC4490-200_wired.jpg|thumb|left|Laird AC4490 wiring example]]
 

{| border="1"
|+ Wiring the Laird AC4868 to the Tiny
|-valign="top"
||'''''AC4868 20-pin Header'''''||'''''Name'''''||'''''Color'''''||'''''Tiny v1.1 Serial-1'''''||'''''Tiny v2.11 Serial'''''||'''''Notes'''''
|-
||2||Tx||green||7||7||''(Note 1)''
|-
||3||Rx||blue||8||8||''(Note 1)''
|-
||5||GND||black||1||1|| -
|-
||10+11||VCC||red||2||3||+3.3v ''(Note 2)''
|-
||17||C/D||white||3||?||Low = Command High = Data
|}
''Note 1 : names are specified with respect to the AEROCOMM module''

''Note 2 : AC4790-1000 needs pins 10 and 11 jumped to work properly''

=== Laird RM024 ===
[[Image:Laird_LT2510_RM024-P125-C-01-side.jpg|thumb|RM024 P125]]
[[Image:Lt2510_prm123.jpg|thumb|LT2510 Modem]]
The RM024 replaces the discontinued LT2510 (they are backwards compatible).

General features:
* Frequency Band 2.4GHz
* Output Power 2,5mW - 125mW
* Sensitivity -98dbm @ 280kbps/-94 dBm @ 500kbps
* RF Data Rate 280/500 kbps
* UART up to 460800 baud
* Power Draw 90mA - 180mA TX / 10mA RX
* Supply Voltage 3.3v
* Range up to 4000m
* Dimensions 26 x 33 x 4mm
* Weight 4 grams
* Interface 20-pin mini connector (smd solder pad or XBee compatible pin header)
* Chip antenna, U.FL antenna connector or both
* Price: 29-31€ @ mouser (SMD / XBEE header)

Two different mounting/pinuts are available: 
* smd version: can be soldered on a pcb 
* pin header: standard XBEE pinout (this is the SMD version mounted on a seperate pcb with male pin headers)

Available in two different output power versions:
{|border="1"
|-valign="top"
||''value''||''50mW version''||''125mW version''
|-
|output power
| 2,5 mW - 50 mW
| 2,5 mW - 125 mW
|-
|output power dbm
|4 dbm - 17 dbm
|4 dbm - 21 dbm
|-
|TX drain
|90mA
|<180mA
|-
|max range (280kbps with 2 dbi antenna)
|2400m
|4000m
|-
|approval
|CE for EU, FCC/IC for USA,
Canada PRM122/123 also for Japan
|FCC/IC for USA, Canada
|}

The RM024 uses frequency hopping (FHSS) which needs a client/server model. That means that one modem (most appropriately the ground station modem) needs to be set to server mode. It will transmit a beacon message and have all client modems synchronize to that in a time and frequency hopping scheme manner. For that all modems need to have the same channel (in fact the hopping scheme) and system-id. Clients can be set to auto-channel and auto-system-id to follow any/the first visible server.

====Documentation====
[http://www.lairdtech.com/WorkArea/DownloadAsset.aspx?id=2147488576 RM024 User Manual] 
[http://www.lairdtech.com/WorkArea/linkit.aspx?LinkIdentifier=id&ItemID=4379 LT2510 User Manual] 
[http://www.lairdtech.com/zips/Developer_Kit.zip Windows configuration tool]

'''Setup'''

Look at the [[Laird_RM024_setup page]]

== Bluetooth ==
These modems do not give you a great range but Bluetooth can be found in a lot of recent laptops built-in. Maybe not useful for fixed wing aircrafts it might be used for in-the-shop testing or quadcopters. Make sure you get a recent Class 1 EDR 2.0 stick if you buy one for your computer.
{|
|
=== RN-41 Bluetooth module(Sparkfun's WRL-08497) ===
* Frequency Band 2.4GHz
* Output Power 32 mW
* RF Data Rate up to ~300 kbps in SPP
* Interface Data Rate up to 921 kbps
* Power Draw (typical) 50 mA TX / 40 mA RX
* Supply Voltage 3.3v
* Range (typical, depends on antenna & environment) 100 meters line-of-sight
* Dimensions 26 x 13 x 2mm
* Weight ~1.5 grams
* Interface solder connector
* price : 20€
|
[[Image:roving_nw_wiring.jpg|thumb|Roving Networks modem wiring]]
|-
|

To connect to it, get the MAC address of the bluetooth modem

me@mybox:~$ hcitool scan
Scanning ...
00:06:66:00:53:AD FireFly-53AD

either make a virtual connection to a Bluetooth serial port each time you connect

sudo rfcomm bind 0 00:06:66:00:53:AD

or configure it once in /etc/bluetooth/rfcomm.conf

rfcomm0 {
bind yes;
device 00:06:66:00:53:AD;
}

now you can use Bluetooth as '''/dev/rfcomm0''' with the Paparazzi 'link'. You might need to restart 'link' in case you get out of range and it disconnects (tbd). Set the Tiny serial speed to 115200 as the modules come preconfigured to that.
|}

== Telemetry via Video Transmitter==

[[Image:video_tx_small.jpg|thumb|2.4GHz Video Transmitter]]
In order for the UAV to transmit video from an onboard camera, an analog video transmitter can be used. These vary in power, and thus range, and run normally on 2.4Ghz. Small UAVs can get about 600m of range from the 50mW version, and extended range can be achieved using units up to 1W. Weight for these units varies from a couple grams to about 30 for the 1W with shielding. Please check for your countries regulations on 2.4Ghz transmission, as each is different.

It is possible to use the audio channel to send simple telemetry data to the groundstation. Uploading telemetry not possible via analog audio transmitter only.
 

== Telemetry via Internet / Raspberry Pi==
Not ready yet...

The main link works over the internet and mobile internet.

Most UMTS sticks don't have a own public IP adress and can't be used as a server. The ssh connection must be reversed(ssh server runs on the gcs, not on the uav)

How to:
*Establish the connection between a UMTS stick and the Raspberry PI, search for each programm for seperate instructions, these on instructables aren't complete ! [http://www.instructables.com/id/Raspberry-Pi-as-a-3g-Huawei-E303-wireless-Edima/#step1 Instructables site]

A android smartphone is another way to provide the Raspberry pi with a internet connection. [http://www.therasberrypi.com/how-to-usb-tether-android-to-your-raspberry-pi Android USB thetering setup]

*set up ser2net
*set up static ip adress (public) of your gcs [http://www.cyberciti.biz/tips/howto-ubuntu-linux-convert-dhcp-network-configuration-to-static-ip-configuration.html static IP Ubuntu]
*set up reverse ssh tunnel [http://www.tunnelsup.com/tup/2013/05/08/raspberry-pi-phoning-home-using-a-reverse-remote-ssh-tunnel ssh reverse serial tunnel]

*connect Raspberry PI with AP over UART (Raspberry Pi's UART Pins are only 3.3v and not 5v tollerant)
== Old / not supported ==
Modules in these cathegory have issues with paparazzi are discontinued by the manufacturer.
Maybe hey will be deleted soon.

=== Laird / Aerocom AC4868-250 ===
'''This module was discontinued by the manufacturer'''
[[Image:ConnexLink_USB_RF_Modem.jpg|thumb|Aerocomm USB Stand-alone Modem]]
* Frequency Band 868MHz (For Europe). 868MHz is a limited band. Please read the [[868MHz Issues]]
* Output Power (w/ 2dBi antenna) 250 mW
* Sensitivity (@ full RF data rate) -103 dB
* RF Data Rate Up to 28.8 Kbps
* INterface Data Rate Up to 57.6 Kbps
* Power Draw (typical) 240 mA TX / 36 mA RX
* Supply Voltage 3.3v & 5V or 3.3v only
* Range (typical, depends on antenna & environment) Up to 15 kilometers line-of-sight
* Dimensions 49 x 42 x 5mm
* Weight < 21 grams
* Interface 20-pin mini connector
* Antenna MMCX jack Connector
* price : 64€

=== Radiotronix ===
These Radiotronix modems are used in transparent mode. Use the WI232EUR Evaluation Software for configuring the modems for the set speed. Connect /CMD and CTS for programming. The DTS version for the US market might cause severe interference with GPS reception, it is not recommended. For a nice ground station modem just add a FTDI232 USB->serial cable, a 3.3V regulator with 100nF capacitors from supplies to ground, solder a SMA cable/connector and put it in a nice case. Make sure you only connect RTS to /CMD if you want to reprogram the modem with the Evaluation software (see the open jumper connection in the picture, green wire) and leave it floating otherwise as connected RTS/CTS sporadically leads to a reprogramming of the modem. The ANT-GXD105-FME/F from [http://www.roundsolutions.com Roundsolutions] was used as a ground station antenna at many competitions. Note that a 1/2 wave dipole antenna works best on-board as it doesn't require a ground-plane and has a reasonably omnidirectional radiation pattern.
{|
|
==== WI232EUR ====
'''This Module has been discontinued by the manufacturer'''
* Frequency Band: 868 MHz (for Europe)
* Output Power: 32 mW
* RF Data Rate: Up to 76.8 kbps
* Interface Data Rate: up to 115.2 kbps
* Power Draw (typical): 65 mA TX / 20 mA RX
* Supply Voltage: 3.3v
* Range (typical, depends on antenna & environment): 500 meters line-of-sight
* Dimensions: 24 x 21 x 4mm
* Weight: ~2 grams
* Interface: solder connector
* Antenna: solder connector
* Price: ~25$
[[Image:Wi232eur_wiring.jpg|thumb|WI232EUR Modem (picture shows connection to Tiny 1.1)]]

==== Pinout ====

 

{| border="1"
|+ Wiring the WI232EUR to the Tiny v1.1
|-valign="top"
||'''''WI232 pins'''''||'''''Name'''''||'''''Tiny Serial-1'''''||'''''Notes'''''
|-
||6||TxD||7||''(Note 1)''
|-
||5||RxD||8||''(Note 1)''
|-
||15-18||GND||1|| -
|-
||19||VCC||2||+3.3v
|-
||4||/CMD||-||''(Note 2)''
|-
||7||CTS||-||''(Note 3)''
|}
''Note 1 : names are specified with respect to the Radiotronix module''

''Note 2 : connect to RTS to program device with Evaluation software''

''Note 3 : connect to CTS to program device with Evaluation software''

|
[[Image:Wi232eur_bopla.jpg|thumb|WI232EUR Modem in BOPLA case]]
|-
|
|}

==== Documentation ====
* [http://www.radiotronix.com/datasheets/new/eur_um.pdf WI232EUR data sheet]
* [http://www.radiotronix.com/datasheets/new/rk-eur_um.pdf WI232EUR user's manual]
* [http://www.radiotronix.com/downloads/software/EUR/setup.exe Evaluation software]

=== Digi XBee Pro 900 ===
'''These modules have been discontinued by the manufacturer, new version is XBee Pro 900HP'''

XBee Pro 900 modules are long range embedded RF modules for US applications. Purpose-built for exceptional RF performance, XBee-Pro 900 modules are ideal for applications with challenging RF environments, such as urban deployments, or where devices are several kilometers apart.

==== Documentation ====
* [ftp://ftp1.digi.com/support/documentation/90000903_a.pdf ftp://ftp1.digi.com/support/documentation/90000903_a.pdf]

=== Coronis WaveCard ===

These relatively inexpensive and light modules implement a Coronis proprietary protocol. Low power consumption - high latency - I would not recommend these modules mostly because of the low quality of the distribution and support. The documentation is rather poor and not easily available.

'''Suport for these modems has been removed from the airborne code on Dec 10th, 2007.'''
{|
|-valign="top"
|
* Frequency Band 400MHz, 868Mhz and 915MHz (3 versions)
* Output Power 25mW and 500mW (2 versions)
* Sensitivity -110 dBm (@ 9600 bps)
* Data Rate 100 Kbps
* Power Draw (typical) 45mA (25mW), 450mA (500mW) TX / 15 mA RX
* Supply Voltage ...
* Range (typical, depends on antenna & environment) Up to 1km (25mW) , 5km (500mW) line-of-sight
* Dimensions 30 x 28 x 7mm (25mW), 37 x 30 x 7mm (500mW)
* 50 ohm RF port for antenna connection
|
[[Image:wavecard.jpg|Coronis Wavecard]]
|}

==== Documentation ====

* [http://www.coronis-systems.com/produit.php?lang=EN&id=WCA www.coronis-systems.com]
* [[Media:CS-COM-SPRD-WAVECARD-E03B.pdf|Wavecard datasheet]]
== Antennas ==

Here are some examples of lightweight and efficient 868MHz antennas developped by the RF laboratory at ENAC.
[[Image:868mhz_twinstar_antenna_1.jpg|thumb|left|868MHz copper foil antenna attached to the aircraft tail]]
[[Image:868mhz_twinstar_antenna_2.jpg|thumb|left|868MHz copper foil antenna bottom view]]
[[Image:868mhz_ground_antenna.jpg|thumb|left|868MHz ground antenna]]
 

This wiki page might give some ideas about antennas: http://en.wikipedia.org/wiki/Dipole_antenna

[[Category:Hardware]]

Modems

2014-03-05T19:56:03Z

AndrewChambers: Marked 900MHz XBee modems are North America and Australia per Digi's website

The Paparazzi autopilots generally feature a TTL serial port to interface with any common radio modem. The bidirectional link provides real-time telemetry and in-flight tuning and navigation commands. The system is also capable overlaying the appropriate protocols to communicate thru non-transparent devices such as the Coronis Wavecard or Maxstream API-enabled products, allowing for hardware addressing for multiple aircraft or future enhancements such as data-relaying, inter-aircraft communication, RSSI signal monitoring and automatic in-flight modem power adjustment. Below is a list of some of the common modems used with Paparazzi, for details on configuring your modem see the [[Airframe_Configuration#Telemetry_.28Modem.29|Airframe Configuration]] and [[XBee_configuration|XBee Configuration]] pages.

==General comparison==
'''This is ONLY a comparison between modules which work acceptably'''

All modules listed here work without issue and are generally available.
{| border="1" cellspacing="0" style="text-align:center" cellpadding="2%"
| align="center" style="background:#f0f0f0;"|'''Feature'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_DigiMesh_.2F_802.15.4_.28.22Series_1.22.29|XBee Series 1]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_DigiMesh_.2F_802.15.4_.28.22Series_1.22.29|XBee Pro Series 1]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_ZB_.2F_ZNet_2.5_.28.22Series_2.22.29|XBee Series 2]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_ZB_.2F_ZNet_2.5_.28.22Series_2.22.29|XBee Pro Series 2]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_868LP|XBee 868LP]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_900HP|XBee Pro 900HP]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_XBee_Pro_XSC_900MHz|XBee Pro XSC 900]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Digi_9XTend|Digi 9XTend]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#SiLabs_Si1000_SoC_based_modems|SiLabs Si1000]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#AC4790-200|Aerocom AC4790-200]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#AC4790-1000|Aerocom AC4790-1000]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Laird_RM024|Laird RM024 50mW]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#Laird_RM024|Laird RM024 125mW]]'''
| align="center" style="background:#f0f0f0;"|'''[[Modems#RN-41_Bluetooth_module.28Sparkfun.27s_WRL-08497.29|RN-41 Bluetooth]]'''
|-
| style="background:#f0f0f0;"|'''frequency'''||2,4GHz||2,4GHz||2,4GHz||2,4GHz||868MHz||900MHz||900MHz||900MHz, 2.4GHz||240-960MHz||900MHz||900MHz||2,4GHz||2,4GHz||2,4GHz
|-
| style="background:#f0f0f0;"|'''output power'''||1mW||63mW (US) 10 mW (Int'l)||2mW||63mW||5mW||250mW||250mW||1mW-1W||max 100mW||5-200mW||5-1000mW||2,5-50mW||2,5-125mW||32mW
|-
| style="background:#f0f0f0;"|'''RF speed'''||250kbps||250kbps||250kbps||250kbps||10kbps, 80kbps||10 or 200kbps||10, 20kbps||9.6, 115.2kbps|| ||76.8kbps||76.8kbps||280, 500kbps||280, 500kbps||300kbps
|-
| style="background:#f0f0f0;"|'''antenna'''||chip, wire, rpsma, u.fl||chip, wire, rpsma, u.fl||chip, wire, rpsma, u.fl||chip, wire, rpsma, u.fl||external required||wire, rpsma, u.fl||wire, rpsma, u.fl||rpsma, MMCX||external required||MMCX, internal Antenna||MMCX||u.fl, chip, both||u.fl, chip, both||pcb trace
|-
| style="background:#f0f0f0;"|'''pinout'''||XBee||XBee||XBee||XBee||SMD||XBee||XBee||20 pin 2,54mm/USB||SMD (42 pin LGA)||20 pin mini connector||20 pin mini connector||XBee/SMD||XBee/SMD||SMD
|-
| style="background:#f0f0f0;"|'''price'''||16€||26€||14€||28€||18€||32€||32€||150€||4€||52€||64€||30€||30€||20€
|-
| style="background:#f0f0f0;"|'''for Country'''||Worldwide||Worldwide||Worldwide||Worldwide||Europe||North America, Australia||North America, Australia||Worldwide||Worldwide||North America, Australia||North America, Australia||Europe||North America||Worldwide
|}

==Frequencies==

Analog and digital (video and modem) can NOT be done over the same frequency !!!

You may want to inform yourself about your countries laws ! Different countries allow different frequencies at different power. 
Sending on a wrong frequency or with too much power may end in a serious lawsuit !

== Digi XBee modules ==

Digi (formerly Maxstream) offers an increasing variety of Zigbee protocol modems well suited for Paparazzi in 2.4 GHz, 900MHz and 868Mhz frequencies. The "Pro" series are long range, up to 40km! Standard series are slightly smaller/lighter/lower power consumption and very short range. All versions are all pin compatible and weigh around 2 grams with wire antennas. All Digi modems can be operated in transparent mode (as a serial line replacement) or in "API mode" with hardware addressing, managed networking, and RSSI (signal strength) data with the Paparazzi "Xbee" option.

Four antenna options are offered: RP-SMA, U-FL, wire antenna, chip antenna

* XBee (PRO) ZB (the current series)
* XBee (PRO) ZNet 2.5 (formerly Series 2) (only legacy -> use XBee-PRO ZB)
The XBee & XBee-PRO ZB share hardware (ember stack) with XBee & XBee-PRO ZNet 2.5. As a result, modules can be "converted" from one platform to another by loading different firmware onto a given module.

These two also share the same hardware and can be converted from one to another by flashing a different firmware:
* XBee-PRO 802.15.4 (formerly Series 1)
* XBee-PRO DigiMesh 2.4

'''Note: Modules based on Freescale chipset (formerly Series 1) are not compatible with Ember chipset based modules (Series 2).'''

If only point to point or point to multipoint communication is required 802.15.4 will do the job. These are designed for high data rates and low latency. 
Modules with Zigbee firmware are needed for mesh functionality(communication between the UAV's)

See the [[XBee_configuration|XBee Configuration]] page. This [http://pixhawk.ethz.ch/tutorials/how_to_configure_xbee tutorial] is also good to configure and get started with XBee Pro.

=== Module Comparison ===
{|border="1"
|-valign="top"
||'''Module'''||'''Point-to-Multipoint'''||'''ZigBee/Mesh'''||'''Chipset'''|||'''Software stack'''||'''Frequency'''||'''TX Power normal/PRO'''||'''Notes'''
|-
|'''XBee ZB'''
|
|yes
|Ember
|EmberZNet PRO 3.1 (ZigBee 2007)
|2.4 GHz
|2mW/50mW
|coordinator needed
|-
|'''XBee ZNet 2.5'''
|
|yes
|Ember
|EmberZNet 2.5 ZigBee
|2.4 GHz
|2mW/50mW
|(only legacy -> use XBee-PRO ZB) coordinator needed
|-
|'''XBee DigiMesh 2.4'''
|
|yes
|Freescale
|
|2.4 GHz
|
|all nodes equal (no special coordinators/routers/end-devices)
|-
|'''XBee 802.15.4'''
|yes
|
|Freescale
|
|2.4 GHz
|
|
|-
|'''XBee-PRO 868'''
|yes
|
|?
|
|868 MHz
|500mW
|Only High Power Frequency allowed in the UK. 2.4GHz limited to 10mW
|}

==== Pinout ====

[[Image:Maxstream_Xbee_pinout.jpg|left|thumb|Maxstream XBee pinout]]
 

{|border="1"
|-valign="top"
||''Xbee 20-pin Header''||''Name''||''Notes''||''Suggested Color''||
|-
|1
| +3.3v
| Power
|Red
|-
|2
|DOUT
|Tx output - connect to Autopilot Rx
|Green
|-
|3
|DIN
|Rx input - connect to Autopilot Tx
|Blue
|-
|10
|GND
| Ground
|Black
|}

The image view is from above, top, thus NOT at the side where the connector pins come out

Note : DTR and RTS need to be wired for upgrading firmware

=== GCS Adaptation ===

There are several vendors of hardware to connect the ground XBee radio modem to the GCS computer.

====Adafruit====

[[Image:xbeeadapter_LRG.jpg|thumb|left|Adafruit XBee adapter board]][[Image:xbeeadapterftdi_LRG.jpg|thumb|Adafruit XBee adapter with FTDI cable]]
[http://www.adafruit.com/index.php?main_page=product_info&cPath=29&products_id=126 Adafruit] offers a great adapter board kit for the Xbee modules that includes a 5-3.3V voltage regulator, power and activity LEDs, and pins to connect directly to your FTDI cable for $10! Some assembly required.

 

====Droids====

[[Image:XBee_Simple_Board.jpg|thumb|left|XBee Simple Board]]

[[Image:XBee_USB_Board.jpg|thumb|left|XBee USB Board]]

[http://www.droids.it/cmsvb4/content.php?143-990.001-XBee-Simple-Board XBee Simple Board]

Simpler, lighter, smaller footprint, bit more expensive, comes assembled and tested. --GR

[http://www.droids.it/cmsvb4/content.php?152-990.002-XBee-USB-Board XBee USB Board]

For direct connection to USB (no FTDI cable required)

 

====PPZUAV====

[[Image:FTDI_Utility_Board.jpg|thumb|left|FTDI Utility Board 1.0‎]]

[https://www.ppzuav.com/osc/product_info.php?cPath=13&products_id=111&osCsid=upcl59vp10vdvno35ejl453442 ppzuav.com product link]

FTDI Utility Board 1.0 with FTDI232RL 
On board XBEE connector and molex picoblade connectors.

 

====Sparkfun====

[[Image:XBee_Explorer_USB.jpg|thumb|left|XBee Explorer USB]]

[http://www.sparkfun.com/products/8687 sparkfun.com]

XBee Explorer USB with FTDI232RL

 

=== Digi XBee Pro DigiMesh / 802.15.4 ("Series 1") ===
*Note: Products based on XBee ZNet 2.5 (formerly Series 2) modules do not communicate with products based on XBee DigiMesh / 802.15.4 (formerly Series 1) modules.

These relatively cheap and light modules implement the [http://www.zigbee.org/en/index.asp ZigBee/IEEE 802.15.4] norm. They allow up to 1.6km (1 mile) range (Paparazzi tested to 2.5km (1.5 miles)). The main drawback of using such 2.4Ghz modules for datalink is that it will interfere with the 2.4Ghz analog video transmitters and a inevitable decrease in range when in proximity to any wifi devices. For the plane, get the whip antenna version if you are not planning to build a custom antenna.

{|
|-valign="top"
|[[Image:Xbee_Pro_USB_RF_Modem.jpg|thumb|left|XBee Pro USB Stand-alone Modem (XBP24-PKC-001-UA)]]
|
* Frequency Band 2.4GHz
* Output Power 100mW (Xbee Pro)
* Sensitivity -100 dBm
* RF Data Rate Up to 250 Kbps
* Interface data rate Up to 115.2 Kbps
* Power Draw (typical) 214 mA TX / 55 mA RX
* Supply Voltage 3.3v
* Range (typical, depends on antenna & environment) Up to 1500m line-of-sight
* Dimensions 24 x 33mm
* Weight 4 grams
* Interface 20-pin mini connector
* Chip antenna, ¼ monopole integrated whip antenna or a U.FL antenna connector (3 versions)
* Price: 16€, Pro 26€
|
[[Image:XBee_pro.jpg|thumb|left|XBee Pro OEM Modem]]
|}
Mouser: [http://au.mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMtJacPDJcUJYzVn8vIv7g2fIpf5DCzJqko%3d 888-XBP24-PKC-001-UA] 
NOTE: If you wish to use this unit with another XBee type other than the 802.15.4 (i.e. XBee-PRO ZB) then purchase a modem with the U.fl connector.

==== Documentation ====

* [http://www.maxstream.net/products/xbee/xbee-pro-oem-rf-module-zigbee.php product page]
* [http://www.maxstream.net/products/xbee/datasheet_XBee_OEM_RF-Modules.pdf datasheet]
* [http://www.maxstream.net/products/xbee/product-manual_XBee_OEM_RF-Modules.pdf user manual]
* To program your Xbee you need X-CTU you can download it [http://www.digi.com/support/productdetl.jsp?pid=3352&osvid=57&tp=5&s=316 here]. (only windows)
* explanation on X-CTU [http://www.ladyada.net/make/xbee/configure.html here].
* [http://ftp1.digi.com/support/firmware/update/xbee/ Drivers for XB24 and XBP24 modules]

=== Digi XBee Pro ZB / ZNet 2.5 ("Series 2") ===

The low-power XBee ZB and extended-range XBee-PRO ZB use the ZigBee PRO Feature Set for advanced mesh networking.

{|
|-valign="top"
|[[Image:XBee_Pro_2SB.jpg|thumb|left|Digi XBee Pro ZB]]
|
* Low-cost, low-power mesh networking
* Interoperability with ZigBee PRO Feature Set devices from other vendors*
* Support for larger, more dense mesh networks
* 128-bit AES encryption
* Frequency agility
* Over-the-air firmware updates (change firmware remotely)
* ISM 2.4 GHz operating frequency
* XBee: 2 mW (+3 dBm) power output (up to 400 ft RF LOS range)
* XBee-PRO: 50 mW (+17 dBm) power output (up to 1 mile RF LOS range)
* RPSMA connector, U.FL connector, Chip antenna, or Wired Whip antenna
* price : 14€, Pro 28€
|
|}
These are available from Mouser: 
[http://au.mouser.com/Search/Refine.aspx?Keyword=888-XBP24-Z7WIT-004 888-XBP24-Z7WIT-004] XBee-PRO ZB with whip antenna 
[http://au.mouser.com/Search/Refine.aspx?Keyword=XBP24-Z7SIT-004 888-XBP24-Z7SIT-004] XBee-PRO ZB with RPSMA

See [[XBee_configuration|XBee Configuration]] for setup.

==== Documentation ====
* [http://www.digi.com/products/wireless/zigbee-mesh/xbee-zb-module.jsp http://www.digi.com/products/wireless/zigbee-mesh/xbee-zb-module.jsp]

=== Digi XBee Pro 868 ===

'''WARNING - THESE MODEMS HAVE A 10% DUTY CYCLE, AND CURRENTLY HAVE SEVERE ISSUES WITH PAPARAZZI'''

868MHz is a limited band. Please read the [[868MHz Issues]]

XBee-PRO 868 modules are long range embedded RF modules for European applications. Purpose-built for exceptional RF performance, XBee-PRO 868 modules are ideal for applications with challenging RF environments, such as urban deployments, or where devices are several kilometers apart.

{|
|-valign="top"
|[[Image:xbeeproxsc-rpsma.jpg|thumb|left|Maxstream XBee Pro 868]]
|
* 868 MHz short range device (SRD) G3 band for Europe
* Software selectable Transmit Power
* 40 km RF LOS w/ dipole antennas
* 80 km RF LOS w/ high gain antennas (TX Power reduced)
* Simple to use peer-to-peer/point-to-mulitpoint topology
* 128-bit AES encryption
* 500 mW EIRP
* 24 kbps RF data rate
* price : ~70 USD
|
|}

See [[XBee_configuration#XBee_Pro_868_MHZ|XBee Configuration]] for setup.

==== Documentation ====
* [http://www.digi.com/products/wireless/point-multipoint/xbee-pro-868.jsp http://www.digi.com/products/wireless/point-multipoint/xbee-pro-868.jsp]

=== Digi XBee 868LP ===

XBee 868LP modules are a low-power 868 MHz RF module for use in Europe. The range is shorter than it's brother the XBee PRO-868, but it can use the 868 G4 band with hopping which does not have restrictions on it's duty cycle. This is a big advantage if one want to have a good stream of telemetry data

{|
|-valign="top"
|[[Image:868lp.jpg|thumb|left|XBee 868LP]]
|
* 868 MHz short range device (SRD) G4 band for Europe
* 4 km RF LOS w/ u.fl antennas
* 5 mW EIRP
* 10 or 80 kbps RF data rate
* price : 18€
|
|}

==== Documentation ====
* [http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/zigbee-mesh-module/xbee-868lp#overview http://www.digi.com/products/wireless-wired-embedded-solutions/zigbee-rf-modules/zigbee-mesh-module/xbee-868lp#overview]

==== Trial ====

With a quickly crafted and not optimal positioned antenna on the airframe we managed to get the advertised 4000 meter range. Data throughput was not high and the Iridium Telemetry XML configuration document was therefore used. All in all, cheap, easy to setup, pin compatible with regular modules and quite a range and usable in Europe without hassle.

=== Digi XBee Pro 900HP ===
* Frequency band 900Mhz
* RF rate 10 or 200 kbps
* up to 250mW output power
* 5 to 8 gramm
* price: 32€

==== Documentation ====
[http://ftp1.digi.com/support/documentation/90002173_H.pdf http://ftp1.digi.com/support/documentation/90002173_H.pdf]

=== Digi XBee Pro XSC 900MHz ===

Maxstream has recently announced a promising new line of modems combining the small size and low cost of their popular Xbee line with the long range and 2.4 GHz video compatibility of their high end 900 MHz models. Sounds like the perfect modem for anyone who can use 900 MHz. Give them a try and post your results here!
{|
|-valign="top"
|[[Image:xbeeproxsc-rpsma.jpg|thumb|left|Maxstream XBee Pro XSC]]
|
* Frequency Band 900 MHz
* Output Power 100 mW (+20 dBm)
* Sensitivity -100 dBm
* RF Rate: 10 or 20 kbps
* Range (typical, depends on antenna & environment) Up to 24km (15 miles) line-of-sight
* Interface 20-pin mini connector (Xbee compatible pinout)
* RPSMA, integrated whip antenna or U.FL antenna connector (3 versions)
* price : 32€
|
|}

==== Documentation ====
* [http://www.digi.com/products/wireless/point-multipoint/xbee-pro-xsc.jsp http://www.digi.com/products/wireless/point-multipoint/xbee-pro-xsc.jsp]

==== Trials ====
Tested one today and it worked great. Going to try a multiUAV test with it soon
--Danstah
 
 
MultiUAV tests concluded this is probably not the best module to use. Even though it says you can change the baudrate inside x-ctu that is not the case, it is fixed at 9600 bps. This is a great modem however for single UAV's and I do recommend.
--Danstah
 
 
Why would the European (868 MHz) be good to 24kbps and this only to 9600? When I was altering my XBees (2.4Ghz Pro's) I had this problem altering baud rates until I read you have to send a "commit and reboot" type command after setting the baud rate. Could this be the case? --GR

=== Digi 9XTend ===

These larger units have been tested on the 900Mhz band, but are also available in 2.4Ghz. They are a bit on the heavy side, about 20 grams, but give good performance at range. They have adjustable transmit power settings from 100mW to 1W. Testing has shown range up to 5.6km (3.5 Miles) with XTend set to 100mW with small 3.1dB dipole antenna.

{|
|-valign="top"
|
[[Image:XTend_USB_RF_Modem.jpg|frame|left|9XTend USB Modem]]
|
* Frequency Band 900Mhz and 2.4Ghz (2 versions)
* Output Power 1mW to 1W software selectable
* Sensitivity -110 dBm (@ 9600 bps)
* RF Data Rate 9.6 or 115.2 Kbps
* Interface data rate up to 230.4 Kbps
* Power Draw (typical) 730 mA TX / 80 mA RX
* Supply Voltage 2.8 to 5.5v
* Range (typical, depends on antenna & environment) Up to 64km line-of-sight
* Dimensions 36 x 60 x 5mm
* Weight 18 grams
* Interface 20-pin mini connector or USB
* RF connector RPSMA (Reverse-polarity SMA) or MMCX (2 versions)
* price : 150€
|
[[Image:Xtend_module.jpg|frame|left|9XTend OEM Modem]]
|}

==== Pinout ====

[[Image:Maxstream_9XTend_Pinout.gif|thumb|left|Maxstream 9XTend Pinout]]

{| border="1"
|-valign="top"
||'''''9XTend 20-pin Header'''''||'''''Name'''''||'''''Tiny Serial-1 Header'''''||'''''Notes'''''
|-
||1||GND||1 (GND)||Ground
|-
||2||VCC||2 (5V)||5V power (150mA - 730mA Supplied from servo bus or other 5V source)
|-
||5||RX||8 (TX)||3-5V TTL data input - connect to Tiny TX
|-
||6||TX||7 (RX)||5V TTL data output - connect to Tiny RX
|-
||7||Shutdown||2||This pin must be connected to the 5V bus for normal operation
|}
Notes: 
* 9XTend can run on voltages as low as 2.8V but users are strongly advised against connecting any modem (especially high power models) to the sensitive 3.3V bus supplying the autopilot processor and sensors.
 

==== Documentation ====

* [http://www.maxstream.net/products/xtend/oem-rf-module.php product page]
* [http://www.maxstream.net/products/xtend/datasheet_XTend_OEM_RF-Module.pdf datasheet]
* [http://www.maxstream.net/products/xtend/product-manual_XTend_OEM_RF-Module.pdf user manual]

==== Configuration ====

These modems need to be carefully configured based on your usage scenario to obtain the best possible range and link quality. In addition, it is always good to make sure the firmware is up to date.

Some typical configurations that may work well, but can still depend your particular situation, are given below. For further details, be sure to consult the XTend users manual. Your application may need a different or modified configuration. The radiomodems do not need identical settings and can in fact be optimized with different settings. A good example is delays and retries: if each radio has the same number of retries and no delay, when a collision occurs each will continuously try to re-transmit, locking up the transmission for some time with no resolution or successful packet delivery. Instead, it is best to set the module whose data should have a lower latency to have no delay and a lower number of retries, while the other module has a delay set (RN > 0) and a greater number of retries. See acknowledged mode example below.

* Acknowledged Polling Mode ('''Recommended'''):
** This causes one radio to be the base and the other(s) to be the remote(s). It eliminates collisions because remotes do not send data unless requested by the base. It can work in acknowledged mode (RR>0), basic reliable mode (MT>0) or in basic mode (no acknowledgement or multiple packets). It is recommended that the lower latency and/or higher data rate side be configured as the base (i.e. if you are sending lots of telemetry then the air module configured as the base is probably a good idea, but if you are using datalink joystick control, the ground side might be better as the base. It may require some experimentation).
* Acknowledged Point-to-(Multi)Point Mode:
** Each radio sends a packet and requests and acknowledgement that the packet was sent from the receiving side. The retries and delays must be set appropriately to ensure packet collisions are dealt with appropriately. It can also work without acknowledgements in basic reliable mode (MT>0) without any acknowledgements (RR=0, MT=0). Some experimentation may be required.

{| border="1"
|-valign="top"
||'''''Setting Name'''''||colspan="2"|'''''Acknowledged Mode'''''||colspan="2"|'''''Polling Mode (Acknowledged)'''''||'''''Notes'''''
|-
|| ||'''''Airside Module'''''||'''''Groundside Module'''''||'''''Base Module'''''||'''''Remote Module'''''||
|-
||BD||6||6||6||6||Adjust to match your configured autopilot and ground station baud rates (default for these is 57600bps)
|-
||DT||default||default||0x02||0x01||Can be adjusted if consistency maintained across addressing functionalities (see manual)
|-
||MD||default||default||3 (0x03)||4 (0x04)||
|-
||MT||0||0||0||0||Use this to enable Basic Reliable transmission, link bandwidth requirement increases (see manual)
|-
||MY||default||default||0x01||0x02||Can be adjusted if consistency maintained across addressing functionalities (see manual)
|-
||PB||default||default||0x02||default||Can be adjusted if consistency maintained across addressing functionalities (see manual)
|-
||PD||default||default||default||default||Can be adjusted to increase polling request rate and DI buffer flush timeout (see manual)
|-
||PE||default||default||0x02||default||Can be adjusted if consistency maintained across addressing functionalities (see manual)
|-
||PL||default||default||default||default||''Transmit power level should be reduced for lab testing!!''
|-
||RN||0 (0x00)||8 (0x08)||default||default||
|-
||RR||6 (0x06)||12 (0x0C)||6 (0x06)||12 (0x0C)||
|}

'''Note:''' All settings are assumed to be default except those listed. Those listed are in decimal unless hex 0x prefix included. Depending on your firmware version, slight modifications may be necessary.

Here is some additional information and alternative instructions to configure the polling mode from the Digi site: [http://www.digi.com/support/kbase/kbaseresultdetl?id=2178 Polling Mode for the 9XTend Radio Modem]

== SiLabs Si1000 SoC based modems ==

The Si1000 radio System on Chip (SOC) produced by SiLabs is found in a number of radio modules, for example the cheap and widely used HopeRf module. There is [https://github.com/tridge/SiK open source firmware] for these radios which makes them suitable for use in MAVs.

Note that (unlike some XBee modules) the SiK firmware does not support mesh topologies, it is strictly a point-to-point link. If you are working with swarming vehicles they may not be the best choice.

Online documentation for the Sik firmware shows how to configure it for various jurisdictions. The firmware supports 433 MHz, 470 MHz, 868 MHz and 900 MHz radios, if you are aware of any hardware supporting the European spectrum licences (868 MHz) please add them to this wiki.

Note: When using a SiK firmware radio with paparazzi, you should set "ATS6=0" (MavLink packing off) and configure paparazzi for transparent serial mode.

[http://www.rfdesign.com.au/index.php/rfd900 This module] is well proven and supports antenna diversity. A combination of 6dbi Yagi plus a dipole on the ground station, with a pair of orthogonality oriented dioples in the airframe, has been extensively tested and proven reliable at >8km range (theoretical range of ~40km).

Alternatively, for shorter range a pair of cheap generic HopeRF-based modems [http://rctimer.com/index.php?gOo=goods_details.dwt&goodsid=815 such as these]

The RFD900 can be paired with cheap generic (single front-end) modules, if for example you use a small short range airframe with a ground station that's also used for long range operations.

== Laird (ex Aerocom) ==
Lairds's API mode is already implemented but some system integration is required. Full API more with addressed packets works well and was tested with AC4790-1x1 5mW low power modules. Maximim range achieved with a whip quater-wave antenna was 1Km.

How to use this modem on ground station side? [http://paparazzi.enac.fr/wiki/index.php/User:SilaS#SDK-AC4868-250_ground_modem_part]

See folder paparazzi3 / trunk / sw / aerocomm. It has all the required files to use this modem on the airborne and ground station side. The link.ml file is a direct replacement of the "main" link.ml file of the ground sttaion and will be merged into it in the future.. or you can do it as well.

{|
|
=== AC4790-200 ===
* Frequency 902-928MHz (North America, Australia, etc).
* Output Power 5-200mW
* Sensitivity (@ full RF data rate) -110dB
* RF Data Rate up to 76.8 Kbps
* INterface Data Rate Up to Up to 115.2 Kbps
* Power Draw (typical) 68 mA
* Supply Voltage 3.3v & 5.5V
* Range (typical, depends on antenna & environment) Up to 6.4 kilometers line-of-sight
* Dimensions 42 x 48 x 5mm
* Weight < 20 grams
* Interface 20-pin mini connector
* Antenna MMCX jack Connector or internal
* price : 52€
|
[[Image:ac4868_transceiver.jpg|thumb|left|AC4868 OEM Modem]]
|
|-
|
=== AC4790-1000 ===
* Frequency 902-928MHz (North America, Australia, etc).
* Output Power 5-1000mW
* Sensitivity (@ full RF data rate) -99dB
* RF Data Rate up to 76.8 Kbps
* INterface Data Rate Up to Up to 115.2 Kbps
* Power Draw (typical) 650 mA
* Supply Voltage 3.3V only
* Range (typical, depends on antenna & environment) Up to 32 kilometers with high-gain antenna
* Dimensions 42 x 48 x 5mm
* Weight < 20 grams
* Interface 20-pin mini connector
* Antenna MMCX jack Connector
* price : 64€
|}

=== Pinout ===

[[Image:Aerocomm_AC4868_pinout.jpg|thumb|left|Laird AC4868 modem pinout]]
[[Image:Aerocomm_AC4490-200_wired.jpg|thumb|left|Laird AC4490 wiring example]]
 

{| border="1"
|+ Wiring the Laird AC4868 to the Tiny
|-valign="top"
||'''''AC4868 20-pin Header'''''||'''''Name'''''||'''''Color'''''||'''''Tiny v1.1 Serial-1'''''||'''''Tiny v2.11 Serial'''''||'''''Notes'''''
|-
||2||Tx||green||7||7||''(Note 1)''
|-
||3||Rx||blue||8||8||''(Note 1)''
|-
||5||GND||black||1||1|| -
|-
||10+11||VCC||red||2||3||+3.3v ''(Note 2)''
|-
||17||C/D||white||3||?||Low = Command High = Data
|}
''Note 1 : names are specified with respect to the AEROCOMM module''

''Note 2 : AC4790-1000 needs pins 10 and 11 jumped to work properly''

=== Laird RM024 ===
[[Image:Laird_LT2510_RM024-P125-C-01-side.jpg|thumb|RM024 P125]]
[[Image:Lt2510_prm123.jpg|thumb|LT2510 Modem]]
The RM024 replaces the discontinued LT2510 (they are backwards compatible).

General features:
* Frequency Band 2.4GHz
* Output Power 2,5mW - 125mW
* Sensitivity -98dbm @ 280kbps/-94 dBm @ 500kbps
* RF Data Rate 280/500 kbps
* UART up to 460800 baud
* Power Draw 90mA - 180mA TX / 10mA RX
* Supply Voltage 3.3v
* Range up to 4000m
* Dimensions 26 x 33 x 4mm
* Weight 4 grams
* Interface 20-pin mini connector (smd solder pad or XBee compatible pin header)
* Chip antenna, U.FL antenna connector or both
* Price: 29-31€ @ mouser (SMD / XBEE header)

Two different mounting/pinuts are available: 
* smd version: can be soldered on a pcb 
* pin header: standard XBEE pinout (this is the SMD version mounted on a seperate pcb with male pin headers)

Available in two different output power versions:
{|border="1"
|-valign="top"
||''value''||''50mW version''||''125mW version''
|-
|output power
| 2,5 mW - 50 mW
| 2,5 mW - 125 mW
|-
|output power dbm
|4 dbm - 17 dbm
|4 dbm - 21 dbm
|-
|TX drain
|90mA
|<180mA
|-
|max range (280kbps with 2 dbi antenna)
|2400m
|4000m
|-
|approval
|CE for EU, FCC/IC for USA,
Canada PRM122/123 also for Japan
|FCC/IC for USA, Canada
|}

The RM024 uses frequency hopping (FHSS) which needs a client/server model. That means that one modem (most appropriately the ground station modem) needs to be set to server mode. It will transmit a beacon message and have all client modems synchronize to that in a time and frequency hopping scheme manner. For that all modems need to have the same channel (in fact the hopping scheme) and system-id. Clients can be set to auto-channel and auto-system-id to follow any/the first visible server.

====Documentation====
[http://www.lairdtech.com/WorkArea/DownloadAsset.aspx?id=2147488576 RM024 User Manual] 
[http://www.lairdtech.com/WorkArea/linkit.aspx?LinkIdentifier=id&ItemID=4379 LT2510 User Manual] 
[http://www.lairdtech.com/zips/Developer_Kit.zip Windows configuration tool]

'''Setup'''

Look at the [[Laird_RM024_setup page]]

== Bluetooth ==
These modems do not give you a great range but Bluetooth can be found in a lot of recent laptops built-in. Maybe not useful for fixed wing aircrafts it might be used for in-the-shop testing or quadcopters. Make sure you get a recent Class 1 EDR 2.0 stick if you buy one for your computer.
{|
|
=== RN-41 Bluetooth module(Sparkfun's WRL-08497) ===
* Frequency Band 2.4GHz
* Output Power 32 mW
* RF Data Rate up to ~300 kbps in SPP
* Interface Data Rate up to 921 kbps
* Power Draw (typical) 50 mA TX / 40 mA RX
* Supply Voltage 3.3v
* Range (typical, depends on antenna & environment) 100 meters line-of-sight
* Dimensions 26 x 13 x 2mm
* Weight ~1.5 grams
* Interface solder connector
* price : 20€
|
[[Image:roving_nw_wiring.jpg|thumb|Roving Networks modem wiring]]
|-
|

To connect to it, get the MAC address of the bluetooth modem

me@mybox:~$ hcitool scan
Scanning ...
00:06:66:00:53:AD FireFly-53AD

either make a virtual connection to a Bluetooth serial port each time you connect

sudo rfcomm bind 0 00:06:66:00:53:AD

or configure it once in /etc/bluetooth/rfcomm.conf

rfcomm0 {
bind yes;
device 00:06:66:00:53:AD;
}

now you can use Bluetooth as '''/dev/rfcomm0''' with the Paparazzi 'link'. You might need to restart 'link' in case you get out of range and it disconnects (tbd). Set the Tiny serial speed to 115200 as the modules come preconfigured to that.
|}

== Telemetry via Video Transmitter==

[[Image:video_tx_small.jpg|thumb|2.4GHz Video Transmitter]]
In order for the UAV to transmit video from an onboard camera, an analog video transmitter can be used. These vary in power, and thus range, and run normally on 2.4Ghz. Small UAVs can get about 600m of range from the 50mW version, and extended range can be achieved using units up to 1W. Weight for these units varies from a couple grams to about 30 for the 1W with shielding. Please check for your countries regulations on 2.4Ghz transmission, as each is different.

It is possible to use the audio channel to send simple telemetry data to the groundstation. Uploading telemetry not possible via analog audio transmitter only.
 

== Telemetry via Internet / Raspberry Pi==
Not ready yet...

The main link works over the internet and mobile internet.

Most UMTS sticks don't have a own public IP adress and can't be used as a server. The ssh connection must be reversed(ssh server runs on the gcs, not on the uav)

How to:
*Establish the connection between a UMTS stick and the Raspberry PI, search for each programm for seperate instructions, these on instructables aren't complete ! [http://www.instructables.com/id/Raspberry-Pi-as-a-3g-Huawei-E303-wireless-Edima/#step1 Instructables site]

A android smartphone is another way to provide the Raspberry pi with a internet connection. [http://www.therasberrypi.com/how-to-usb-tether-android-to-your-raspberry-pi Android USB thetering setup]

*set up ser2net
*set up static ip adress (public) of your gcs [http://www.cyberciti.biz/tips/howto-ubuntu-linux-convert-dhcp-network-configuration-to-static-ip-configuration.html static IP Ubuntu]
*set up reverse ssh tunnel [http://www.tunnelsup.com/tup/2013/05/08/raspberry-pi-phoning-home-using-a-reverse-remote-ssh-tunnel ssh reverse serial tunnel]

*connect Raspberry PI with AP over UART (Raspberry Pi's UART Pins are only 3.3v and not 5v tollerant)
== Old / not supported ==
Modules in these cathegory have issues with paparazzi are discontinued by the manufacturer.
Maybe hey will be deleted soon.

=== Laird / Aerocom AC4868-250 ===
'''This module was discontinued by the manufacturer'''
[[Image:ConnexLink_USB_RF_Modem.jpg|thumb|Aerocomm USB Stand-alone Modem]]
* Frequency Band 868MHz (For Europe). 868MHz is a limited band. Please read the [[868MHz Issues]]
* Output Power (w/ 2dBi antenna) 250 mW
* Sensitivity (@ full RF data rate) -103 dB
* RF Data Rate Up to 28.8 Kbps
* INterface Data Rate Up to 57.6 Kbps
* Power Draw (typical) 240 mA TX / 36 mA RX
* Supply Voltage 3.3v & 5V or 3.3v only
* Range (typical, depends on antenna & environment) Up to 15 kilometers line-of-sight
* Dimensions 49 x 42 x 5mm
* Weight < 21 grams
* Interface 20-pin mini connector
* Antenna MMCX jack Connector
* price : 64€

=== Radiotronix ===
These Radiotronix modems are used in transparent mode. Use the WI232EUR Evaluation Software for configuring the modems for the set speed. Connect /CMD and CTS for programming. The DTS version for the US market might cause severe interference with GPS reception, it is not recommended. For a nice ground station modem just add a FTDI232 USB->serial cable, a 3.3V regulator with 100nF capacitors from supplies to ground, solder a SMA cable/connector and put it in a nice case. Make sure you only connect RTS to /CMD if you want to reprogram the modem with the Evaluation software (see the open jumper connection in the picture, green wire) and leave it floating otherwise as connected RTS/CTS sporadically leads to a reprogramming of the modem. The ANT-GXD105-FME/F from [http://www.roundsolutions.com Roundsolutions] was used as a ground station antenna at many competitions. Note that a 1/2 wave dipole antenna works best on-board as it doesn't require a ground-plane and has a reasonably omnidirectional radiation pattern.
{|
|
==== WI232EUR ====
'''This Module has been discontinued by the manufacturer'''
* Frequency Band: 868 MHz (for Europe)
* Output Power: 32 mW
* RF Data Rate: Up to 76.8 kbps
* Interface Data Rate: up to 115.2 kbps
* Power Draw (typical): 65 mA TX / 20 mA RX
* Supply Voltage: 3.3v
* Range (typical, depends on antenna & environment): 500 meters line-of-sight
* Dimensions: 24 x 21 x 4mm
* Weight: ~2 grams
* Interface: solder connector
* Antenna: solder connector
* Price: ~25$
[[Image:Wi232eur_wiring.jpg|thumb|WI232EUR Modem (picture shows connection to Tiny 1.1)]]

==== Pinout ====

 

{| border="1"
|+ Wiring the WI232EUR to the Tiny v1.1
|-valign="top"
||'''''WI232 pins'''''||'''''Name'''''||'''''Tiny Serial-1'''''||'''''Notes'''''
|-
||6||TxD||7||''(Note 1)''
|-
||5||RxD||8||''(Note 1)''
|-
||15-18||GND||1|| -
|-
||19||VCC||2||+3.3v
|-
||4||/CMD||-||''(Note 2)''
|-
||7||CTS||-||''(Note 3)''
|}
''Note 1 : names are specified with respect to the Radiotronix module''

''Note 2 : connect to RTS to program device with Evaluation software''

''Note 3 : connect to CTS to program device with Evaluation software''

|
[[Image:Wi232eur_bopla.jpg|thumb|WI232EUR Modem in BOPLA case]]
|-
|
|}

==== Documentation ====
* [http://www.radiotronix.com/datasheets/new/eur_um.pdf WI232EUR data sheet]
* [http://www.radiotronix.com/datasheets/new/rk-eur_um.pdf WI232EUR user's manual]
* [http://www.radiotronix.com/downloads/software/EUR/setup.exe Evaluation software]

=== Digi XBee Pro 900 ===
'''These modules have been discontinued by the manufacturer, new version is XBee Pro 900HP'''

XBee Pro 900 modules are long range embedded RF modules for US applications. Purpose-built for exceptional RF performance, XBee-Pro 900 modules are ideal for applications with challenging RF environments, such as urban deployments, or where devices are several kilometers apart.

==== Documentation ====
* [ftp://ftp1.digi.com/support/documentation/90000903_a.pdf ftp://ftp1.digi.com/support/documentation/90000903_a.pdf]

=== Coronis WaveCard ===

These relatively inexpensive and light modules implement a Coronis proprietary protocol. Low power consumption - high latency - I would not recommend these modules mostly because of the low quality of the distribution and support. The documentation is rather poor and not easily available.

'''Suport for these modems has been removed from the airborne code on Dec 10th, 2007.'''
{|
|-valign="top"
|
* Frequency Band 400MHz, 868Mhz and 915MHz (3 versions)
* Output Power 25mW and 500mW (2 versions)
* Sensitivity -110 dBm (@ 9600 bps)
* Data Rate 100 Kbps
* Power Draw (typical) 45mA (25mW), 450mA (500mW) TX / 15 mA RX
* Supply Voltage ...
* Range (typical, depends on antenna & environment) Up to 1km (25mW) , 5km (500mW) line-of-sight
* Dimensions 30 x 28 x 7mm (25mW), 37 x 30 x 7mm (500mW)
* 50 ohm RF port for antenna connection
|
[[Image:wavecard.jpg|Coronis Wavecard]]
|}

==== Documentation ====

* [http://www.coronis-systems.com/produit.php?lang=EN&id=WCA www.coronis-systems.com]
* [[Media:CS-COM-SPRD-WAVECARD-E03B.pdf|Wavecard datasheet]]
== Antennas ==

Here are some examples of lightweight and efficient 868MHz antennas developped by the RF laboratory at ENAC.
[[Image:868mhz_twinstar_antenna_1.jpg|thumb|left|868MHz copper foil antenna attached to the aircraft tail]]
[[Image:868mhz_twinstar_antenna_2.jpg|thumb|left|868MHz copper foil antenna bottom view]]
[[Image:868mhz_ground_antenna.jpg|thumb|left|868MHz ground antenna]]
 

This wiki page might give some ideas about antennas: http://en.wikipedia.org/wiki/Dipole_antenna

[[Category:Hardware]]

Subsystem/ins

2014-03-04T17:16:49Z

AndrewChambers: Added details about alt_float based on reading the source code

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages hideprefix=always>Subsystems</categorytree>
== INS subsystem ==
The INS (Inertial Navigation System) subsystem specifies which position and velocity estimation algorithm you are using.

Most of the INS filters are only providing position and speed, and they need to be used together with an AHRS filter for attitude. Currently, only the experimental invariant filter is a full INS.

Currently possible AHRS subsystem types are
* alt_float
* gps_passthrough
* xsens
* xsens700
* no_type
* hff
* extended
* ardrone2
* float_invariant

e.g. for the extended filter:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="ins" type="extended"/>
</firmware>
</source>
}}

== Implementations ==

=== alt_float ===
Filters altitude and climb rate for fixedwings.

A 2-state Kalman filter that estimates vertical position and vertical velocity from GPS and barometric data.

When USE_BAROMETER is true:
* GPS horizontal position and horizontal velocity is directly passed through
* GPS vertical position sets the altitude for the barometric reference pressure (QFE)
* Vertical position and velocity is a filtered based on barometric pressure with respect to the reference pressure and GPS vertical velocity readings.

When USE_BAROMETER is false or undefined:
* GPS velocity is directly passed through to the vehicle's state.
* GPS horizontal position is directly passed through.
* Altitude is filtered based on GPS height and vertical velocity data.

'''Parameters'''

USE_BAROMETER - Enables the use of barometric data

DEBUG_ALT_KALMAN - Enables debug messages from the subsystem (Default: not defined)

=== GPS passthrough (gps_passthrough) ===

=== xsens ===
XSens Mti-G

<source lang="xml">
<subsystem name="ins" type="xsens">
<configure name="XSENS_UART_NR" value="0"/>
<configure name="XSENS_UART_BAUD" value="B115200"/>
</subsystem>
</source>

=== xsend700 ===
XSens Mti-G

<source lang="xml">
<load name="ins_xsens_MTiG_fixedwing.xml">
<configure name="XSENS_UART_NR" value="0"/>
</load>
</source>

=== no_type ===
simple INS with float vertical filter

<source lang="xml">
<subsystem name="ins"/>
</source>

=== Horizontal Filter Float (hff) ===
simple with float vertical and horizontal filters for INS

=== extended ===
extended INS with vertical filter using sonar in a better way (flap ground)

=== ardrone2 ===
simple INS with float vertical filter

=== float_invariant ===
attitude and speed estimation for fixedwings via invariant filter

[[Category:User_Documentation]] [[Category:Subsystems]]

Subsystem/ins

2014-03-04T02:17:17Z

AndrewChambers: fleshing out the sections with descriptions from the conf files

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages hideprefix=always>Subsystems</categorytree>
== INS subsystem ==
The INS (Inertial Navigation System) subsystem specifies which position and velocity estimation algorithm you are using.

Most of the INS filters are only providing position and speed, and they need to be used together with an AHRS filter for attitude. Currently, only the experimental invariant filter is a full INS.

Currently possible AHRS subsystem types are
* alt_float
* gps_passthrough
* xsens
* xsens700
* no_type
* hff
* extended
* ardrone2
* float_invariant

e.g. for the extended filter:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="ins" type="extended"/>
</firmware>
</source>
}}

== Implementations ==

=== alt_float ===

=== GPS passthrough (gps_passthrough) ===

=== xsens ===
XSens Mti-G

<source lang="xml">
<subsystem name="ins" type="xsens">
<configure name="XSENS_UART_NR" value="0"/>
<configure name="XSENS_UART_BAUD" value="B115200"/>
</subsystem>
</source>

=== xsend700 ===
XSens Mti-G

<source lang="xml">
<load name="ins_xsens_MTiG_fixedwing.xml">
<configure name="XSENS_UART_NR" value="0"/>
</load>
</source>

=== no_type ===
simple INS with float vertical filter

<source lang="xml">
<subsystem name="ins"/>
</source>

=== Horizontal Filter Float (hff) ===
simple with float vertical and horizontal filters for INS

=== extended ===
extended INS with vertical filter using sonar in a better way (flap ground)

=== ardrone2 ===
simple INS with float vertical filter

=== float_invariant ===
attitude and speed estimation for fixedwings via invariant filter

Subsystem/ins

2014-03-04T01:53:36Z

AndrewChambers: Created the start of the INS subsystem page

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages hideprefix=always>Subsystems</categorytree>
== INS subsystem ==
The INS (Inertial Navigation System) subsystem specifies which position and velocity estimation algorithm you are using.

Most of the INS filters are only providing position and speed, and they need to be used together with an AHRS filter for attitude. Currently, only the experimental invariant filter is a full INS.

Currently possible AHRS subsystem types are
* alt_float
* gps_passthrough
* xsens
* xsens700
* no_type
* hff
* extended
* ardrone2
* float_invariant

e.g. for the extended kalman filter:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="ins" type="extended"/>
</firmware>
</source>
}}

== Implementations ==

TODO

Module/GPS UBlox UCenter

2014-03-03T23:15:18Z

AndrewChambers: Better separation of basic and advanced configuration options

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Modules</categorytree>
If you use a µ-blox GPS without flash memory, this module will take over the task of initializing the GPS for you when you power your autopilot.

It has auto-baudrate to detect the current GPS baudrate, and configures all message rates and communication ports. The module will send a DEBUG message (ID 26) that indicates the firmware version in your GPS, the previous baudrate, and the reply for each configuration step. To enable and view the message, you will need to define DEBUG_GPS_UBX_UCENTER as TRUE in your [[Airframe_Configuration|airframe configuration]] file and select to receive that message in your [[Telemetry|telemetry]] file. See the example below for more details.

It will configure the following settings:
* set baudrate to GPS_BAUD (typically either 38400 or 57600)
* enable the NAV_POSLLH, NAV_VELNED, NAV_STATUS, NAV_SVINFO, NAV_SOL
* disable UTM on old Lea4P by not sending NAV_POSUTM
* enable SBAS
* configure it to 3D only fix
* set the internal dynamic model to Airborne 2G

== Basic ==

Add the gps_ubx_ucenter [[Modules|module]] to the "modules" section in your aircraft configuration file:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml"/>
</modules>
</source>
}}

== Advanced ==

You can specify to a different dynamic model for the u-blox.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml">
<define name="GPS_UBX_NAV5_DYNAMICS" value="NAV5_DYN_PORTABLE" />
</load>
</modules>
</source>
}}

You can specify to receive a DEBUG message over telemetry. Make changes to both the airframe and telemetry config files.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<modules>
...
<load name="gps_ubx_ucenter.xml">
<define name="GPS_UBX_NAV5_DYNAMICS" value="NAV5_DYN_PORTABLE" />
<define name="DEBUG_GPS_UBX_UCENTER" value="TRUE" />
</load>
</modules>
</source>
}}

{{Box Code|conf/telemetry/myplane.xml|
<source lang="xml">
<mode name="default">
...
<message name="DEBUG" period="0.5"/>
</mode>
</source>
}}
[[Category:User_Documentation]] [[Category:Modules]]

Module/GPS UBlox UCenter

2014-03-03T23:12:31Z

AndrewChambers: Added frames with file names for source code examples

Module/GPS UBlox UCenter

2014-03-03T23:01:32Z

AndrewChambers: Updated to document pull request #653

Subsystem/gps

2014-02-25T19:38:26Z

AndrewChambers: Describing location to find default values

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages hideprefix=always>Subsystems</categorytree>
Currently possible GPS subsystems are
{| class="wikitable" style="text-align:center" border="1"
! type !! architectures !! firmwares !! notes
|-
|''ublox'' || all || all || recommended
|-
|''ublox_utm'' || all || fixedwing || for the older ublox4 series that still have a UTM message
|-
|''skytraq'' || all || rotorcraft || some fields missing in the skytraq protocol for fixedwings, see [https://github.com/paparazzi/paparazzi/issues/167 #167, fixed]
|-
|''mediatek_diy '' || all || fixedwing ||
|-
|''nmea'' || stm32 || all || only basic position and fix information, see [https://github.com/paparazzi/paparazzi/issues/120 #120, fixed]
|}

Just specify the appropriate subsystem in your firmware section.
{{Box Code|conf/airframes/myplane.xml|
<pre>
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="gps" type="ublox"/>
</firmware>
</pre>
}}

=== Configure Options ===
If a configure option is not specified the default is used.

* '''GPS_PORT''': ''UART0'', ''UART1'', etc.
** default: The correct UART is already defined according to your board.
* '''GPS_BAUD''': ''B4800'', ''B9600'', ''B38400'', ''B57600'', ''B115200''
** default: Already defined according to your board (e.g. ''B38400'' for Lisa/M v2.0).
* '''GPS_LED''': ''1'', ''2'', ''3'', ''none''
** default: Already defined according to your board (e.g. ''2'' for tiny2 or twog).

Defaults can be found in the board makefile (e.g. conf/boards/ardrone2_raw.makefile).

If you use different baud rates or UART set the according parameters, e.g.
{{Box Code|conf/airframes/myplane.xml|
<pre>
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="gps" type="ublox">
<configure name="GPS_BAUD" value="B9600"/>
<configure name="GPS_PORT" value="UART0"/>
<configure name="GPS_LED" value="none"/>
</subsystem>
</firmware>
</pre>
}}

'''Notes:'''
* u-blox GPS modules are factory configured for 9600 baud, 38,400 baud is recommended along with the other required changes. The GPS can be accessed directly thrugh the [[tunnel|UART Tunnel]] and [[GPS#GPS_configuration_using_U-Center|Configured with u-center]]
* You can also use the [[Module/GPS_UBlox_UCenter|GPS u-blox U-Center module]] to automatically configure baudrate and messages for your u-blox GPS on startup.

[[Category:User_Documentation]] [[Category:Subsystems]]

FlightGear

2014-02-22T00:18:20Z

AndrewChambers: Fixed outdated instructions for installing FlightGear on Ubuntu

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Simulation</categorytree>
__TOC__

FlightGear Flight Simulator.

See http://www.flightgear.org/

== Installation ==

=== Debian/Ubuntu ===
The standard Debian/Ubuntu repositories contain FlightGear 2.4 or 2.6.

The latest edition of FlightGear is available from Launchp PPA (contributed by Saikrishna Arcot).

Install flightgear:
sudo add-apt-repository ppa:saiarcot895/flightgear
sudo apt-get update
sudo apt-get install flightgear

==== From source ====

A great page to read in case you want to install Flightgear from source [http://wiki.flightgear.org/Scripted_Compilation_on_Linux_Debian/Ubuntu can be found here]

== Adding Paparazzi models ==
There are a few new models that come with paparazzi:
* ''mikrokopter.xml'' quadrotor frame
* ''hexa.xml'' hexacopter
* ''simple_bipe.xml'' biplane/quadrotor hybrid (transitioning vehicle)

To make them available in flightgear, make a link from ''/usr/share/games/flightgear/Models/Aircraft/paparazzi'' to ''<paparazzi_dir>/conf/simulator/flightgear/''
sudo ln -s $PAPARAZZI_SRC/conf/simulator/flightgear/ /usr/share/games/flightgear/Models/Aircraft/paparazzi

== Using FlightGear for Visualization ==
For Flight Gear visualization of the simulation, version 2.6 or greater is best. If you wish to use version 2.4 or lower, you must add the following to the firmware section of your airframe file:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<define name="FG_2_4" value="1"/>
...
</firmware>
</source>
}}

* Launch Flight Gear with the following command:
fgfs --fdm=null --native-gui=socket,in,30,,5501,udp
or to e.g. use the mikrokopter quadrotor model:
fgfs --fdm=null --native-gui=socket,in,30,,5501,udp --prop:/sim/model/path=Models/Aircraft/paparazzi/mikrokopter.xml

[[Category:Simulation]] [[Category:Software]]

Subsystem/actuators

2014-02-21T23:46:24Z

AndrewChambers: Added missing ardrone2 as a possible actuator subsystem

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages>Subsystems</categorytree>
This subsystem only needs be explicitly specified for rotorcrafts where there are several different actuators implementations and you have to add the correct one depending on the ESCs you use.

Currently possible actuators subsystems are
* ''mkk''
* ''asctec''
* ''asctec_v2''
* ''pwm_supervision''
* ''skiron''
* ''heli''
* ''ardrone2''

== MKK ==
Mikrokopter ESCs
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="rotorcraft">
...
<subsystem name="actuators" type="mkk">
<configure name="MKK_I2C_SCL_TIME" value="50"/> 
</subsystem>
<define name="I2C_TRANSACTION_QUEUE_LEN" value="10"/> 
</firmware>
</source>
}}

* ''MKK_I2C_SCL_TIME'' is specific to LPC21x based boards (e.g. booz) and has no effect for STM32 based boards (e.g. Lisa/M/L)

=== XML configuration ===
required defines in section ''ACTUATORS_MKK'':
* ''NB'': number of motors
* ''ADDR'': the I2C addresses of your motors
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<section name="ACTUATORS_MKK" prefix="ACTUATORS_MKK_">
<define name="NB" value="4"/>
<define name="ADDR" value="{ 0x52, 0x54, 0x56, 0x58 }"/>
</section>
</source>
}}
The order of addresses in the list defines the numbering of motors! Warn on this during motor mixing!

You also need the matching [[Rotorcraft_Configuration#Motor_Mixing|Motor Mixing section]].
MKK specific values for SUPERVISION defines:
* ''STOP_MOTOR'' : 0, optional, as the default is already 0
* ''MIN_MOTOR'' : 3
* ''MAX_MOTOR'' : 200

== Asctec v1 ==
These controllers already to the mixing themselves, so the [[Rotorcraft_Configuration#Motor_Mixing|Motor Mixing section]] section is not needed.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="rotorcraft">
...
<subsystem name="actuators" type="asctec"/>
</firmware>
</source>
}}

== Asctec v2 ==
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="rotorcraft">
...
<subsystem name="actuators" type="asctec_v2"/>
</firmware>
</source>
}}
=== XML configuration ===
You need the matching [[Rotorcraft_Configuration#Motor_Mixing|Motor Mixing section]].

== PWM Supervision ==
Only for stm32 based autopilot boards (eg. Lisa/M, Lisa/L)
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="rotorcraft">
...
<subsystem name="actuators" type="pwm_supervison">
<define name="SERVO_HZ" value="400"/>
</subsystem>
</firmware>
</source>
}}

The define ''SERVO_HZ'' sets a higher update frequency for the pwm controllers which is needed for good response times.
=== XML configuration ===
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<servos min="0" neutral="0" max="0xff">
<servo name="FRONT" no="0" min="1000" neutral="1000" max="2000"/>
<servo name="BACK" no="1" min="1000" neutral="1000" max="2000"/>
<servo name="LEFT" no="2" min="1000" neutral="1000" max="2000"/>
<servo name="RIGHT" no="3" min="1000" neutral="1000" max="2000"/>
</servos>
</source>
}}
You also need the matching [[Rotorcraft_Configuration#Motor_Mixing|Motor Mixing section]].
Example PWM specific values for SUPERVISION defines:
* ''STOP_MOTOR'' : 800
* ''MIN_MOTOR'' : 1000
* ''MAX_MOTOR'' : 2000

[[Category:User_Documentation]] [[Category:Subsystems]]

Subsystem/ahrs

2014-02-21T18:10:21Z

AndrewChambers: Explain that converting from nanotesla to unit vector

<categorytree style="float:right; clear:right; margin-left:1ex; border: 1px solid gray; padding: 0.7ex;" mode=pages hideprefix=always>Subsystems</categorytree>
== AHRS subsystem ==
The '''A'''ttitude and '''H'''eading '''R'''eference '''S'''ystem subsystem specifies which attitude estimation filter you are using.

Currently possible AHRS subsystem types are
* ''[[Subsystem/ahrs#Complementary_Quaternion_.28fixed_point.29|int_cmpl_quat]]''
* ''[[Subsystem/ahrs#Complementary_Quaternion.2FRotation_Matrix_.28floating_point.29|float_cmpl]]''
* ''[[Subsystem/ahrs#DCM_.28floating_point.29|float_dcm]]''
* ''[[Subsystem/ahrs#Complementary_Euler_.28fixed_point.29|int_cmpl_euler]]''
* ''[[Subsystem/ahrs#Kalman_Filter_Quaternion|float_mlkf]]''
* ''[[Subsystem/ahrs#Infrared|infrared]]''

e.g. for the latest complementary filter:
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="ahrs" type="int_cmpl_quat"/>
</firmware>
</source>
}}

== Implementations ==

There is a test program ( sw/airborne/test/ahrs/compare_ahrs.py ) to compare different AHRS implementations on simple test cases.

'''Caution!''' '''Please also see [https://github.com/paparazzi/paparazzi/issues/93 issue 93] about proper handling of BODY_TO_IMU in all AHRS algorithms.'''

=== Complementary Quaternion (fixed point) ===

To measure attitude angles, gyrometers measurements are integrated. The result of integration is accurate for short term, but gyro bias is accumulated, which results in long term errors (drift).
On the other hand, accelerometers can be used to measure angles directly, but they suffer from noise due to vibrations. The measurement is then only accurate when averaged over a long term. Also, accelerometers alone are unable to give accurate angles when the vehicle is accelerating.
Complementary filter takes advantage of both sensors, using a low-pass filter on accelerometer readings and high pass filter on gyrometers readings, to estimate attitude angles.
* Estimates the gyro bias.
* By default uses magnetometer for heading.
* In v3.9 and later:
** Compensation of centrifugal force via GPS speed (to fly in circles with a fixedwing). Enabled with AHRS_GRAVITY_UPDATE_COORDINATED_TURN which is set by default for a fixedwing firmware.
** GPS based heading estimation: https://github.com/paparazzi/paparazzi/issues/130

Other flags of interest are:
*AHRS_PROPAGATE_LOW_PASS_RATES : apply a low pass filter on rotational velocity
*AHRS_MAG_UPDATE_ALL_AXES : '''available since v3.9''' use mag to also update roll/pitch and not only yaw (not recommended in most cases)
*AHRS_MAG_UPDATE_YAW_ONLY : '''removed in v3.9, default behaviour since''' only update the yaw instead of all axes

* NEW since [https://github.com/paparazzi/paparazzi/commit/b40da0ae56e861e088017c01426d0c4ed7c43350 v5.1_devel-455-gb40da0a]:
** Proper scaling of corrections for 100Hz fixedwing or 500Hz for rotorcraft.
** Allow tuning of the accel and mag correction natural freqency and damping.
** Tunable gravity_heuristic_factor to reduce accelerometer influence only when the vehicle is accelerating (norm of ax,ay,az ~ 9,81 m/s2).

* Flags of interest in master branch are:
** AHRS_PROPAGATE_FREQUENCY: IMU gyrometer reading frequency ( Hz, depend on IMU subsystem used and its configuration)
** AHRS_CORRECT_FREQUENCY: IMU accelerometer reading frequency (Hz)
** AHRS_MAG_CORRECT_FREQUENCY: IMU magnetometer reading frequency (Hz)
** AHRS_ACCEL_OMEGA: Complementary filter accelerometer cut-off frequency (rd/s). Default is 0.063 rd/s, the accelerometer reading are "averaged" over 100 seconds (= 2*pi/0.063) to correct gyro bias. Lower the cut-off frequency reduce the influence of accelerometers. WARNING: if ACCEL_OMEGA is set at a lower frequency, the gyro bias variations may not be corrected fast enough. As a result, the computed attitude may show significant static (or low frequency) errors. If accel_omega is set higher, the gyro bias will be well corrected and the static accuracy of the computed angle will be very good, but the dynamic error of the computed angle may be bad.
** AHRS_ACCEL_ZETA: Complementary filter accelerometer damping. Default is 0.9
** AHRS_MAG_OMEGA:Complementary filter magnetometer cut-off frequency (rd/s). Default is 0.04 rd/s. Acts the same as accelerometer but on the yaw axis.
** AHRS_MAG_ZETA:Complementary filter magnetometer damping. Default is 0.9
** AHRS_GRAVITY_HEURISTIC_FACTOR: Default is 30. Reduce accelerometer cut-off frequency when the vehicle is accelerating: norm(ax,ay,az) ~ 9,81 m/s2. WARNING: when the IMU is not well damped, the norm of accelerometers never equals to 9,81 m/s2. As a result, the GRAVITY_HEURISTIC_FACTOR will reduce the accelerometer bandwith even if the vehicle is not accelerating. Set AHRS_GRAVITY_HEURISTIC_FACTOR = 0 in case of vibrations.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="ahrs" type="int_cmpl_quat"/>
</firmware>

<section name="AHRS" prefix="AHRS_">
<define name="H_X" value=" 0.51562740288882"/>
<define name="H_Y" value="-0.05707735220832"/>
<define name="H_Z" value=" 0.85490967783446"/>
</section>
</source>
}}

Also see the [[Subsystem/ahrs#Local_Magnetic_Field|Local Magnetic Field]] section.


No danger of [http://en.wikipedia.org/wiki/Gimbal_lock gimbal lock], since quaternions are used.
 
Suitable for fixedwings. Needs GPS!
 
Suitable for rotorcraft if the magnetometer is calibrated.
 
The arithmetic is [http://en.wikipedia.org/wiki/Fixed-point_arithmetic fixed point] and is thus suitable if the processor (on your board) has no [http://en.wikipedia.org/wiki/Floating_point_unit FPU].


=== Complementary Quaternion/Rotation Matrix (floating point) ===
* Estimates the gyro bias.
* By default uses magnetometer for heading.
* You need to define either ''AHRS_PROPAGATE_RMAT'' or ''AHRS_PROPAGATE_QUAT'' (select if the propagation is done in rotation matrix or quaternion representation).
* In v3.9 and later:
** Compensation of centrifugal force via GPS speed (to fly in circles with a fixedwing). Enabled with AHRS_GRAVITY_UPDATE_COORDINATED_TURN which is set by default for a fixedwing firmware.
** GPS based heading estimation: https://github.com/paparazzi/paparazzi/issues/130
Other flags of interest are:
* AHRS_PROPAGATE_LOW_PASS_RATES : apply a low pass filter on rotational velocity
* AHRS_MAG_UPDATE_ALL_AXES : use mag to also update roll/pitch and not only yaw (not recommended in most cases)
* AHRS_GRAVITY_UPDATE_NORM_HEURISTIC: lower the gain of the gravity update based on a acceleration norm heuristic (e.g. good for bungee takeoff)

{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="rotorcraft or fixedwing">
...
<subsystem name="ahrs" type="float_cmpl_rmat">
<define name="AHRS_PROPAGATE_QUAT"/>
</subsystem>
</firmware>

<section name="AHRS" prefix="AHRS_">
<define name="H_X" value=" 0.51562740288882"/>
<define name="H_Y" value="-0.05707735220832"/>
<define name="H_Z" value=" 0.85490967783446"/>
</section>
</source>
}}

Also see the [[Subsystem/ahrs#Local_Magnetic_Field|Local Magnetic Field]] section.


No danger of [http://en.wikipedia.org/wiki/Gimbal_lock gimbal lock], since quaternions are used.
 
Suitable for fixedwings. Needs GPS!
 
Suitable for rotorcraft if the magnetometer is calibrated.
 
The arithmetic is [http://en.wikipedia.org/wiki/Floating_point floating point] and is thus '''not''' suitable if the processor (on your board) has '''no''' [http://en.wikipedia.org/wiki/Floating_point_unit FPU].


=== DCM (floating point) ===
* No direct gyro bias estimation, but also compensates for attitude drift.
* Uses GPS speed for heading.
* Compensation of centrifugal force via GPS speed (to fly in circles with a fixedwing).
* '''Careful, it doesn't handle all BODY_TO_IMU rotations (mounting positions) correctly!'''

The algorithm was developed by William Premerlani and Paul Bizard. The theory can be found here: [[Media:DCMDraft2.pdf|DCMDraft2.pdf]] The algorithm is also used in the AHRS systems of the AdruIMU.
The name DCM for the algorithm is really a misnomer, as that just means that the orientation is represented as a '''D'''irection'''C'''osine'''M'''atrix (rotation matrix). But since people already know it under that name, we kept it.

Other flags of interest are:
*USE_MAGNETOMETER : use magnetometer to update yaw (untested ? The magnetometer code has to be improved, since ferromagnetic materials affect the magnetic field. This is currently not implemented.)

{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="rotorcraft or fixedwing">
...
<subsystem name="ahrs" type="float_dcm"/>
</firmware>
</source>
}}


Possible danger of [http://en.wikipedia.org/wiki/Gimbal_lock gimbal lock], since quaternions are not used.
 
Suitable for fixedwings with GPS.
 
Possibly suitable for rotorcraft if the magnetometer is used to determine the yaw and well calibrated, which seems to be questionable at the moment.
<= This information needs an update (see info above)!
 
The arithmetic is [http://en.wikipedia.org/wiki/Floating_point floating point] and is thus '''not''' suitable if the processor (on your board) has '''no''' [http://en.wikipedia.org/wiki/Floating_point_unit FPU].


=== Complementary Euler (fixed point) ===
* Not recommended for fixedwings, as this filter doesn't compensate for centrifugal force when flying turns.
* Magnetometer is always only used for heading (yaw).
* '''Does not handle the accel and mag updates correctly if BODY_TO_IMU is used for more than just adjustment by a few degrees.'''
* In general, rather use ''[[Subsystem/ahrs#Complementary_Quaternion_.28fixed_point.29|int_cmpl_quat]]''

Optional flags/defines are:
* FACE_REINJ_1 : defaults to 1024
* IMU_MAG_OFFSET : offset to subtract from the heading calculated by the magnetometer
* USE_NOISE_FILTER : apply a simple filter on the rate and accel inputs
* USE_NOISE_CUT : cut rate input at 1 rad/s and accel input at 20m/s²

{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="fixedwing or rotorcraft">
...
<subsystem name="ahrs" type="int_cmpl_euler"/>
</firmware>

<section name="MISC">
<define name="FACE_REINJ_1" value="1024"/> 
</section>
</source>
}}


Possible danger of [http://en.wikipedia.org/wiki/Gimbal_lock gimbal lock], since quaternions are not used.
 
Repeat from above: '''Not''' suitable for fixedwings.
 
Suitable for rotorcraft. The magnetometer is used to determine the yaw and needs to be calibrated.
Recommended replacement: [[Subsystem/ahrs#Complementary_Quaternion_.28fixed_point.29|int_cmpl_quat]]
 
The arithmetic is [http://en.wikipedia.org/wiki/Fixed-point_arithmetic fixed point] and is thus suitable if the processor (on your board) has no [http://en.wikipedia.org/wiki/Floating_point_unit FPU].


=== Kalman Filter Quaternion ===
Multiplicative Linearized [http://en.wikipedia.org/wiki/Kalman_filter Kalman Filter] in quaternion formulation.
* Available in v5.0 and later
* Estimates the gyro bias.
* Uses magnetometer to update all 3 axes.
{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<firmware name="rotorcraft">
...
<subsystem name="ahrs" type="float_mlkf"/>
</firmware>

<section name="AHRS" prefix="AHRS_">
<define name="H_X" value=" 0.51562740288882"/>
<define name="H_Y" value="-0.05707735220832"/>
<define name="H_Z" value=" 0.85490967783446"/>
</section>
</source>
}}

Also see the [[Subsystem/ahrs#Local_Magnetic_Field|Local Magnetic Field]] section.


No danger of [http://en.wikipedia.org/wiki/Gimbal_lock gimbal lock], since quaternions are used.
 
'''Not''' suitable for fixedwings!
 
Suitable for rotorcraft. The magnetometer is used and needs to be well calibrated.
Estimates attitude and heading. Does not use GPS.
 
The arithmetic is [http://en.wikipedia.org/wiki/Floating_point floating point] and is thus '''not''' suitable if the processor (on your board) has '''no''' [http://en.wikipedia.org/wiki/Floating_point_unit FPU].


=== Infrared ===
For use with infrared sensors that detect aircraft attitude and the [[Module/infrared| infrared module]].

== Local Magnetic Field ==
[[Image:Noaa_mag_data.png|thumb|right|200px|Screenshot of noaa page]]
[[Image:Normalised_mag_fields.png|thumb|right|200px|Screenshot of scilab page]]
'''This is needed if the magnetometer should be used !''' 
Take also a look at [[ImuCalibration#Calibrating_for_the_Earth_magnetic_field| magnetometer calibration]] which should be done to increase accuracy !

First the values of the local magnetic field vector are needed. They can be found at the states geological institute.

USA [http://www.ngdc.noaa.gov/geomag-web/#igrfwmm ngdc.noaa.gov]

Needed values are:
* north component (x)
* east component (y)
* vertical component (z)

The vector components are in nanotesla (nT) but AHRS needs these values as a unit vector (the lengh of a unit vector is 1), so they need to be converted.

'''Convert them:'''

Copy the north(x), east(y), and vertical(z) component values into scilab and execute "X/norm(X)" or run this in ipython:

<source lang=python>
import numpy as np
x = np.array([20875.1, 8480.2, -51279.8])
x/np.linalg.norm(x)
</source>

or enter this into [http://wolframalpha.com Wolfram Alpha]:
<source lang=python>
Normalize[{20875.1, 8480.2, -51279.8}]
</source>
[[Category:User_Documentation]] [[Category:Subsystems]]

Lastly, enter the results into your airframe file as H_X, H_Y, and H_Z:

{{Box Code|conf/airframes/myplane.xml|
<source lang="xml">
<section name="AHRS" prefix="AHRS_">
<define name="H_X" value="0.372692"/>
<define name="H_Y" value="0.151401"/>
<define name="H_Z" value="-0.915521"/>
</section>
</source>
}}