PX4 on STM32F4Discovery

We'll try to run the PX4 firmware on the STM32F4Discovery board.  Some documentation can be found here.   We'll try to run everything from Linux.

First, we build the PX4 bootloader for f4discovery.  There is a specific makefile target, make px4discovery_bl.  To flash the bootloader, we can use texane stlink, which we will build.  After installing it, we can run stlink-gui and download the bootloader through the mini USB port, detected as STMicroelectronics ST-LINK/V2.

Then we build the PX4 firmware with make px4-stm32f4discovery_default.  We connect to the micro USB port; it is detected as PX4 BL DISCOVERY and /dev/ttyACM0 port is created.  To flash, make px4-stm32f4discovery_default upload.

Connect a USB Serial adapter to PA3 (RX) and PA2 (TX), and run screen /dev/ttyUSB0 57600 to access NuttX terminal.  The boot message, 

sercon: Registering CDC/ACM serial driver

sercon: Successfully registered the CDC/ACM serial driver

HW arch: PX4_STM32F4DISCOVERY

FW git-hash: 7a82c777b28c49b3476be3da716984e6bdc987a9

FW version: 7.82.77 0 (122834176)

OS: NuttX

OS version: Release 7.22.0 (118882559)

OS git-hash: 63775322bf25adb406594f8e610122fe0cef2f7a

Build datetime: Jun 22 2018 22:25:57

Build uri: BUILD_URI

Toolchain: GNU GCC, 4.9.3 20150529 (prerelease)

MFGUID: 3138343532314719002e0034

MCU: STM32F???, rev. Z

UID: 2E0034:32314719:31383435

nsh: mount: mount failed: No such file or directory

nsh: tone_alarm: command not found

nsh: mkfatfs: mkfatfs failed: No such file or directory

nsh: tone_alarm: command not found

nsh: tune_control: command not found

nsh: mtd: command not found

INFO  [param] selected parameter default file /fs/microsd/params

ERROR [param] open '/fs/microsd/params' failed (2)

nsh: rgbled: command not found

nsh: blinkm: command not found

nsh: rgbled_pwm: command not found

  BAT_N_CELLS: curr: 0 -> new: 3

ERROR [param] Parameter SYS_USE_IO not found

ERROR [param] Parameter SYS_FMU_TASK not found

ERROR [param] Parameter MNT_MODE_IN not found

ERROR [param] Parameter MNT_MODE_OUT not found

nsh: dataman: command not found

nsh: gps: command not found

nsh: fmu: command not found

nsh: fmu: command not found

nsh: ms5611: command not found

nsh: ms5611: command not found

nsh: bst: command not found

nsh: adc: command not found

ERROR [param] Parameter SENS_EN_LL40LS not found

ERROR [param] Parameter SENS_EN_LL40LS not found

ERROR [param] Parameter SENS_EN_SF0X not found

ERROR [param] Parameter SENS_EN_SF1XX not found

ERROR [param] Parameter SENS_EN_MB12XX not found

ERROR [param] Parameter SENS_EN_TRANGER not found

ERROR [param] Parameter SENS_EN_TFMINI not found

ERROR [param] Parameter SENS_EN_LEDDAR1 not found

nsh: sensors: command not found

nsh: commander: command not found

nsh: send_event: command not found

nsh: load_mon: command not found

ERROR [param] Parameter UAVCAN_ENABLE not found

ERROR [param] Parameter SENS_EN_LL40LS not found

ERROR [param] Parameter TRIG_MODE not found

nsh: fmu: command not found

nsh: tune_control: command not found

nsh: mavlink: command not found

nsh: mavlink: command not found

ERROR [param] Parameter UAVCAN_ENABLE not found

nsh: mavlink: command not found

nsh: navigator: command not found

No autostart ID found

nsh: ekf2: command not found

nsh: tone_alarm: command not found

ERROR [param] Parameter MNT_MODE_IN not found

nsh: vmount: command not found

ERROR [param] Parameter SDLOG_MODE not found

ERROR [param] Parameter SDLOG_MODE not found

nsh: logger: command not found

nsh: mavlink: command not found

NuttShell (NSH)

nsh> ERROR [parameters] failed to open param file: /fs/microsd/params

ERROR [parameters] param save failed (-1)

nsh> help

help usage:  help [-v] [<cmd>]

  [           dirname     free        mkrd        rmdir       umount

  ?           date        help        mh          set         unset

  basename    dd          hexdump     mount       sh          usleep

  break       df          kill        mv          sleep       xd

  cat         echo        ls          mw          test

  cd          exec        mb          ps          time

  cp          exit        mkdir       pwd         true

  cmp         false       mkfatfs     rm          uname

Builtin Apps:

  cu

  bl_update

  config

  mixer

  nshterm

  param

  perf

  px4_simple_app

  reboot

  top

  uorb

  ver

  sercon

  serdis

nsh> ver all

HW arch: PX4_STM32F4DISCOVERY

FW git-hash: 7a82c777b28c49b3476be3da716984e6bdc987a9

FW version: 7.82.77 0 (122834176)

OS: NuttX

OS version: Release 7.22.0 (118882559)

OS git-hash: 63775322bf25adb406594f8e610122fe0cef2f7a

Build datetime: Jun 22 2018 22:25:57

Build uri: BUILD_URI

Toolchain: GNU GCC, 4.9.3 20150529 (prerelease)

MFGUID: 3138343532314719002e0034

MCU: STM32F???, rev. Z

UID: 2E0034:32314719:31383435

nsh>

Fan Speed Measurement

I have an application that requires the fan speed measurement.  We can use some photo detector and a light source between the fan blades as an encoder.

The CdS photoresistor cell does not have the speed.  A solar cell salvaged from a broken timer does respond adequately.

The solar cell is enclosed in a box with a small hole exposing the solar cell.  A LED flashlight is pointed at the solar cell through the hole.  The fan blades interrupts the light periodically.  The voltage generated by the solar cell is digitized and the variations are detected and measured to determine the rate.  The fan has 10 blades, at 1000RPM, the pulse rate is about 170Hz.  The scope captures the signal,

If we use a laser point, which has a small beam spot, we get,

Note the rising edge is faster, but the falling edge still has the long tail.