Software Sensor

• For hardware design see: https://github.com/larus-breeze/hw_sensor

Facts

• STM32CubeIDE
• STM32F407VG
• FreeRTOS
• IMU
• GNSS
• Static pressure
• Differential pressure
• CAN interface
• Bluetooth via HM19 (HW-1.0) ESP32 (HW-2.0)
• RS232 NMEA output channels

How to use it

Some usefull git commands to work with this repository and the included submodule command line:

Clone via https:

git clone --recurse-submodules https://github.com/larus-breeze/sw_sensor

Clone via ssh:

git clone --recurse-submodules git@github.com:larus-breeze/sw_sensor.git

Switch to a branch:

git checkout branch_name --recurse-submodules

Pull latest changes:

git pull --recurse-submodules  

STM32 Build Configurations

• Release used for release versions (Max. optimized, no debug info)
• Debug used for development

Flash and prepare the sensor hardware

STM32

• Flash via USB using the STM32CubeProgrammer and a compiled binary sw_sensor.elf file from here: https://github.com/larus-breeze/sw_sensor/releases
  Hold the Boot Button on power-on to start the STM32 in the DFU bootloader mode. Use the STM32CubeProgrammer to flash the binary to the STM32 micro-controller.

ESP32 controller

• Flash the *.ino file in ESP32_Firmware with arduino studio via the esp32 usb connector.
• Optionally: Use the arduino IDE to change the device name and the RF mode (Bluetooth or WLAN).

Prepare an sd-card with configuration files

• put a sensor_config.txt file (template in configuration/) in the sd cards root directory. Adjust the parameters as described in configuration/README.md Initially the heading may be inaccurate as the magnetic calibration algorithm needs some time in the air to find the exact calibration. A 30 minutes flight with some right and left turns should be sufficient to calibrate the compass module.
• Optionally: Create a directory with the name "logger" to enable logging of all measurement data with 100Hz
• Optionally: Create a directory with the name "magnetic" to enable the logging of magnetic calibration events. There should be a few of these events during the calibration process. If you observe frequent additional events you probabely have moving ferromagnetic parts in the vicinity of the magnetometer.

Additional developer options

• Put an empty file with the name: "sensor.readings" in order to switch the serial output format from Larus NMEA syntax to pure sensor raw data values.

Led signal indications

There are LEDs on the PCBs edge which indicate the following

• SD-CARD (blue)
  • Off: No uSD-Card detected
  • On: uSD-Card detected
  • Flashing: Actively logging (writing) to card
• SYSTEM (blue)
  • Off: System not working at all
  • Flashing: Indicates that FreeRTOS and the tasks are running.
• GNSS (blue)
  • Off: No GNSS fix
  • Flashing: GNSS fix
• ERROR (red)
  • Flashing: at least one of the sensors IMU, static pressure, dynamic pressure or GNSS is not working.
  • Sporadic flashing: DGNSS heading fix is briefly missing.
• ESP (blue)
  • Not used currently