SmartProbe v004

SMARTPROBE Pitot3D device

Smartprobe is an autonomous pitot3d tube that is designed to be mounted on a drone. It records relative wind speed and angles, stores them on sdcard, and stream data on a serial line.

Disclaimer : software was still in alpha stage when the project development was stopped in fall 2021

Installation

The easy way

use the latest binary found under GitHub Releases

You really want to compile it ?

Dependencies installation

cross compilation and Perl library for the boardGen.pl tool :

sudo apt install build-essential gcc-arm-none-eabi gdb-multiarch \
         default-jre libmodern-perl-Perl \
	 libxml-libxml-Perl libfile-which-Perl \
	 dfu-util
	 
sudo cpan -i String/LCSS.pm

to use bmpflash when flashing with a Black Magic Probe or Criquet Probe

sudo usermod -a -G dialout $USER

optional : stm32cubemx install from stmicroelectronics website:

https://www.st.com/en/development-tools/stm32cubemx.html (boardGen.pl script needs xml MCU description files) If stm32cubemx is not found, a pregenerated board.h is used, you won't be able to modify pin assignation

clone of GitHub repository and submodules :

git clone --recursive https://github.com/alex31/smartprobe.git
cd smartprobe
git submodule update --init --recursive

build firmware in release mode

make clean; make BUILD=SIZE

flash firmware in release mode

In dfu mode : plug micro-USB cable (no need to power supply)

make BUILD=SIZE dfuflash

In swd mode : plug swd cable (need to power supply smartprobe)

make BUILD=SIZE flash

Usage

µSD Card

It is mandatory to install a micro sd card :

• SD should be formatted with FAT32 or ExFAT filesystem.
• configuration is read from SD
• wind data is stored on the SD
• reading/writing SD can be done
  • offline : SD must be removed
  • online : plug the smartprobe via USB (with SD installed) on a computer, and it will be shown like a USB storage device

Connector J3 at the back

The Molex connector at the back contains :

• power in : Vin should be between 7 and 20 Volts
• bootloader mode switch (connect pin5 with pin6, then power up the smartprobe) -bootloader mode is to be used to flash the firmware in the smartprobe
• USB to mount the sdcard as a USB storage device
• UART which can be used for multiple purposes (choice is made in configuration file)

Parameters

• firmware parameters are read from the SD at start, in a file named smartprobe.conf
• if a file named smartprobe.conf is not found, it will be created, all the fields set at their default value
• the most accurate and up-to-date definitions (with default and range) for each field can be found in source file
  source/confParameters.hpp
• here is a list of parameters (details are missing, confParameters.hpp reading is advised)

Calibration

Smartprobe should be calibrated in a wind tunnel before use. The calibration matrix values should then be written in the configuration file instead of the default values.

Calibration procedure :

...TO BE WRITTEN...

Development tool

there is a SWD connector on the PCB for connecting a debug probe (Black Magic Probe or STlink V2/V3) which permits debugging with gdb and access to a shell console where errors messages are shown.

troubleshooting

The led color reflect status of operation (see details below). When error occurs, the error details are logged in the syslog file, on the sdcard, and on debug console if a probe is attached to the internal swd+serial connector.

error codes :

• blink green : OK
• blink green and orange : sd card file system is dirty, operation will try to continue, but ultimately, there is a need for filesystem check or reformating
• blink orange : sd card mount has failed
• blink green and white : configuration file error
• blink red : hardware fault detected

..

Ideas for future developments

• If external componant (autopilot) stream gps positions and heading, wind in a terrestrial reference frame could be calculated on board
• add USB CDC endoint to the existing USB storage endpoint to output serial console shell via USB
• stream UAVCAN messages on the CAN 2.0B interface