Lisa

Lisa ( the Lost Illusions Serendipitous Autopilot) is a STM32/Overo board designed to run Paparazzi

TODO

List of files currently being edited:

Antoine:

• check JTAG on STM32
• work with Piotr on connecting the missing wires on the STM
• I2C on STM32: (software )
• SPI on STM32: (software )
• USB for gumstix : does 5V need to be switchable ? (to allow reset from the gumstix)
• Check's from sheet 5
• Pressure sensor instruction to gany (redo airspeed computation), so he can finish the schematic for that (or finish it directly in the schematic) ( in progress )
• Check the routing rules below and add if planned on routing a certain part in a specific way
• write layout ideas / wishes

Esden:

• STM32 spelling and connection check
• Fix STM32 footprint pad sizes
• Routing rules that have to be followed
• Add specification of external pressure sensor ADC
• Replace all 0603 parts with versions from pretty-eagle-lib
• Replace all molex connectors with versions from pretty-eagle-lib
• Add a LED shift register (STP08CP05 should do the job)
• Order a STP08CP05 sample
• Test the STP08CP05 on a breadboard
• howto for STM32 gcc gdb toolchain (blinking LED or similar) (started writing one on openhardwarewiki.org)

Gany:

• Check FT2232 footprint hw/lbr/booz.lbr qfn-64 size & pinout
  • -> Changed pad size from 0.6 x 0.4 to 0.75 x 0.25 and moved pin1 indicator outside the chip.
• Make sure STM32 can interrupt overo
  • -> connected omap pin 176 with stm pin 11 via level shifter
• ADC ref and analog supply voltage on STM
• Battery voltage measurement
• make sure overo console serial port is usable when FT2232 is not powered. protect overo console with a gate to allow to connect something to it when FTDI is not powered/used.
• add led to show FT2232 is powered, since power is from USB
• pressure sensor filter and hookup for both sensors
• Bring remaining GPIO of STM to a connector
• Subtract 2V from abs sensor, 0.75 from differential
• Run simulation on filter
• Place components
• Route board
• Send for production 4pcb/pcbcard(china)/sunstone

Hardware

Bill Of Material

Qty	Schematic part name	Value	Description	Package	Manufacturer	Manufacturer part #	Digikey	Mouser
Resistors
foo_qty	foo_schem	foo_val	foo_desc	foo_package	foo_man	foo_man#	foo_dk	foo_mouser
LEDs
4	LED_1 to LED_4	N/A	LED 2x1.2mm RD/GN	foo_package	foo_man	foo_man#	754-1093-1-ND	foo_mouser
LEDs
1	U2	STM32F103RE	Microcontrollers (MCU) 32BIT Cortex M3 Performance LINE	LQFP64	STMicroelectronics	STM32F103RET6	497-6444-ND	511-STM32F103RET6

The hardware is still in development. The current CAD files are maintained in savannah svn in the paparazzi4/trunk/hw/lisa directory. Software development is done on a Overo/Summit + Olimex STM32-H103 dev board

STM32

STM32-F103RE

pinout

SPI1 : IMU/baro high speed sensor communications, STM32 is master

       pin 21 (SCK), 22(MISO), 23(MOSI)  
       accel/gyro 16bitsADC   9(DRDY)  8(SS)
       mag                   24(DRDY) 10(SS)  25(RESET)
       eeprom                         53(SS)
       baro                  40(DRDY) 39(SS)

SPI2 : overo, STM is slave

       pin 33 (SS), 34(SCK), 35(MISO), 36(MOSI),  11(interrupt for OMAP)

I2C1 : motorcontroller

       pin 58(SCL), 59(SDA)

I2C2 : extension

      pin 29(SCL), 30(SDA) 

UART1 : GPS or IMUxsense

      pin 42(TX), 43(RX) 

UART2 : Modem

      pin 16(TX) ,17(RX)

UART3 : RC24

      pin 51(TX), 52(RX)

CAN : motor controller

      pin 42(TX), 43(RX)

SERVO_out: driving 3 servos

      37(TIM3CH1), 38(TIM3CH2), 26(TIM3CH3) 

RC_in: analog RC

      27(TIM3H4)

JTAG : flash and debug

      46(TMS), 49(TCK), 50(TDI), 55(TDO), 56(TRST), 7(RESET)

ADCs : 1 for battery 2/3 for extansion

LED :

      3(LED_CLK), 4(LED_DATA)

POWER_SWITCHES: This is switched supply, used for example to switch on and off a video transmitter or some LEDS for night flight

               Can be removed for lack of place

Pressure sensors

The board is equipped with a pair of pressure sensors, one absolute to measure altitude and one differential to measure airspeed.

Absolute Pressure

The proposed absolute pressure sensor is the freescale MPXh6115 The following plot displays the output of the sensor versus altitude

Differential Pressure

The proposed differential sensor is the MPXV5004DP

Because of high resolution requirements in the pressure sensor circuit there is an external ADC needed with the following features:

• 16bit resolution minimum, 20bit would be awesome
• Two channels (multiplexed or not) each at least 100Hz sampling rate
• I2C or SPI interface (I2C preferred)
  • We used the MAX11040 as ADC for a meteo payload, some (SPI) code is there. It samples 4 channels simultaneously in 24 bits (less "in real"). Slowest conversion speed is 250.1 samples/second.

FT2232

This chip is used for JTAG on STM32 and SERIAL/USB convertion on overo console

datasheet: URL

mini module used for dev : URL

schematics used is from the minimodule as ft2232 and minimodule schematics are not coherent ( regarding pullups of the eeprom)

Software

STM32 drivers for paparazzi

LED : done

SYS_TIME : done

UART : done without DMA, so got datalink, telemetry and RC24 working

I2C : not done, needed for motor controllers

SPI : not done, needed for IMU ( big works as we share with mag and baro) and for overo

CAN : not don, needed for motor controller and CSC

PPMin: not done, needed for analog radio control and windvane

PPMout: not done, needed for servos ( 3 servos ? )

STM32 toolchain

You can use the summon-arm-toolchain script to build the required toolchain. For the default values of the Paparazzi Makefile to work, you should set

PREFIX=/opt/stm32/toolchain/arm-elf and LIBSTM32_EN=1

Open Embedded

Open Embedded is the linux distribution used on the overo. You can follow the instructions on gumstix's website to build a complete cross development environment. Paparazzi's Makefile will default to look for it in /overo-oe

Routing Notes

• Motor controller connectors in 4 corners of the board if possible
• If we are running out of space on the board we have several options:
  • Only one connector for the motors
  • Two connectors for the motors on each side of the board
  • Two connectors for the motors on each side of the board where each connector can accomodate two motor controller wires (4 pins each connector)
  • Servo connector: used to drive up to 3 small servos, for example on a small biplan, or a gimbal for a camera, can also have switched 5V to switch on and OFF the video transmitter

Routing Rules

• 6mil traces/spacings for signals
• 12mil traces/spacings for power traces (this is min value, otherwise as wide as possible or even planes if possible)
• 6mil layout grid
• Layer stacking:
  • Top: Signal + Ground plane
  • Route2: Ground plane(s) (Separate analogue and digital ground)
  • Route15: Power plane(s)
  • Bottom: Signal + Ground plane
• 0.4mm vias with 0.1mm restring