STM32 Telemetry Firmware Code

This repository contains the main Sunseeker STM32 telemetry firmware plus small hardware-test projects. Every firmware directory is a self-contained STM32CubeMX/CubeIDE project.

Quick start: GitHub to STM32CubeIDE

1. Get the code

On this repository's GitHub page, select Code > Download ZIP. Extract the entire ZIP to a normal working directory before opening STM32CubeIDE.

Because this is a public repository, no GitHub account, username, or sign-in is required. If you use Git, select Code, copy the HTTPS URL, and run:

git clone <repository-url>

Do not move an individual project or open files directly from inside the ZIP. Whether you download or clone the repository, keep its directory structure intact because each CubeIDE project links to source files one directory above its STM32CubeIDE folder.

2. Choose a project

Project directory	Target	Purpose
telemetry_adv_v2	STM32F437VG/VI	Newest integrated telemetry revision; the normal starting point for current F437 hardware
telemetry_adv_v1	STM32F437VG/VI	Previous integrated telemetry revision
Telemetry_Reference	STM32F429ZI	Full reference implementation for the older F429 target
Blink_LED	STM32F437VG/VI	LED bring-up test
esp32_testing	STM32F437VG/VI	ESP32/SPI test
gps_testing	STM32F437VG/VI	GPS test
IMU_BME_Testing	STM32F437VG/VI	BMI270 and BME sensor test
RS232_testing	STM32F437VG/VI	RS232 test
RTC_testing	STM32F437VG/VI	Real-time-clock test
SD_Card_test_nd_Can_test	STM32F437VG/VI	SD card and CAN test

The MCU target matters: do not flash the F429 Telemetry_Reference build to the F437 board.

3. Import it into STM32CubeIDE

1. Install STM32CubeIDE and open it with any workspace directory outside this repository.
2. Select File > Import....
3. Select General > Existing Projects into Workspace, then select Next.
4. For Select root directory, browse to the chosen project's nested STM32CubeIDE directory. For example: STM32_Telemetry_Code/telemetry_adv_v2/STM32CubeIDE.
5. Make sure the project is checked. Leave Copy projects into workspace unchecked, then select Finish.

Do not import the repository root or only the .ioc file. CubeIDE detects a project by the hidden .project and .cproject files inside each STM32CubeIDE directory.

4. Build and flash

1. Right-click the imported project and select Clean Project.
2. Select Project > Build Project (or press Ctrl+B). CubeIDE recreates the ignored Debug build directory locally.
3. Connect the correct target through ST-LINK and supply target power.
4. Select Run > Debug As > STM32 C/C++ Application to program and debug, or Run As > STM32 C/C++ Application to program and run.

If CubeIDE asks to migrate the project, allow it, then clean and rebuild. If linked files appear missing, remove the imported project from the workspace without deleting its contents and repeat the import from the nested STM32CubeIDE directory.

Editing the hardware configuration

The .ioc file is stored at the top of each project directory, one level above STM32CubeIDE. It appears as a linked file after a correct import. Open it in CubeIDE to change pins or peripherals and regenerate code. Keep application changes inside CubeMX USER CODE BEGIN / USER CODE END sections so code generation does not overwrite them.

Repository layout

STM32_Telemetry_Code/
|-- README.md
|-- SUNSEEKER_CAN_NETWORK.md
|-- telemetry_adv_v2/
|   |-- telemetry_adv_v2.ioc       # CubeMX hardware configuration
|   |-- Core/                      # Application source and headers
|   |-- Drivers/                   # STM32 HAL and CMSIS
|   |-- FATFS/ and Middlewares/    # Filesystem support
|   `-- STM32CubeIDE/              # Import this directory into CubeIDE
|       |-- .project and .cproject # CubeIDE project metadata
|       `-- Debug/                 # Local generated output; not committed
|-- telemetry_adv_v1/
|-- Telemetry_Reference/
`-- *_testing/                     # Focused hardware-test projects

Generated Debug and Release directories are intentionally excluded from Git. A fresh GitHub download contains the source, libraries, linker scripts, launch configuration, .ioc, and CubeIDE metadata needed to rebuild them.

Firmware overview

This workspace contains different versions of telemetry firmware for the STM32. The Telemetry_Reference project is the full reference firmware and is meant to work with the SD card, real time clock, BME environmental sensor, BMI270 IMU, ESP32-C3, GPS, CAN bus, RS232 output, and status LEDs.

The STM32 sends telemetry out in two main ways:

1. To the ESP32-C3 over SPI, so the ESP32 can forward data to the Bluetooth app.
2. To the RS232 port as a readable raw telemetry block for external displays, logging tools, or debugging.

See SUNSEEKER_CAN_NETWORK.md for the CAN network IDs, payload layout, speed decode notes, and Sunseeker RS232 row mapping.

ESP32 / Bluetooth Telemetry

The ESP32-C3 is connected to the STM32 over SPI. The STM32 sends framed text messages to the ESP32 when the ESP32 ready signal is active. The ESP32 side can then forward those messages to the Bluetooth application.

The STM32 sends three main frame types:

$HDR,<csv header>
$LOG,<sequence number>,<csv telemetry row>
$RSP,<command id>,<OK or ERR>,<message>

Header Frame

The header frame tells the ESP32/app what fields are present in each telemetry row. It is sent before the normal log stream when a header is pending.

$HDR,time_ms,adalogger_rtc,adalogger_rtc_valid,acc_x_mg,...

Log Frame

The log frame is the normal telemetry data stream. It uses the same CSV row format that is written to the SD card.

$LOG,123,time_ms,adalogger_rtc,adalogger_rtc_valid,...

Current CSV fields include:

time_ms
adalogger_rtc
adalogger_rtc_valid
acc_x_mg, acc_y_mg, acc_z_mg
gyr_x_mdps, gyr_y_mdps, gyr_z_mdps
imu_speed_mph
gps_speed_mph
gps_speed_valid
can_speed_mph
can_speed_valid
can_speed_source
gps_lat_deg
gps_lon_deg
gps_fix_valid
gps_fix_age_ms
vehicle_speed_mph
vehicle_speed_source
bme_temp_c
bme_pressure_pa
bme_humidity_pct
can_rx_count
can_id
can_ext
can_dlc
can_data

Response Frame

The response frame is sent when the ESP32 sends a command to the STM32. Response frames are sent before normal log frames so the app can quickly see whether a command succeeded or failed.

$RSP,42,OK,LOG_STARTED
$RSP,43,ERR,SD_NOT_READY

Supported ESP32 commands include:

CMD,<id>,START_LOG
CMD,<id>,STOP_LOG
CMD,<id>,SET_RTC,YYYY-MM-DD,HH:MM:SS

The firmware also accepts direct command text such as START_LOG, STOP_LOG, and SET_RTC,....

RS232 Telemetry

The RS232 output is a human-readable telemetry block. It is intended for the Sunseeker telemetry application display. The UART is configured for 115200 baud.

The block is sent about once per second and uses fixed start/end markers:

raw_data
ABCDEF
...
VWXYZ

Inside the block, the firmware sends:

• Fixed CAN table rows such as MC1BUS, MC1VEL, MC2VEL, DC_DRV, BP_VMX, and others.
• BME temperature, pressure, and humidity.
• A single NAV line containing processed IMU speed, GPS speed, selected vehicle speed, GPS position, fix state, and GPS age.
• A TL_TIM line containing the current telemetry timestamp.

Example RS232 block:

raw_data
ABCDEF
MC1BUS,0xHHHHHHHH,0xHHHHHHHH
MC1VEL,0xHHHHHHHH,0xHHHHHHHH
MC2VEL,0xHHHHHHHH,0xHHHHHHHH
DC_DRV,0xHHHHHHHH,0xHHHHHHHH
BP_VMX,0xHHHHHHHH,0xHHHHHHHH
BME,T=23.65,P=98110.73,H=52.43
NAV,IMU_MPH=0.00,GPS_MPH=0.00,GPS_VALID=0,VEHICLE_MPH=0.00,SOURCE=NONE,LAT=0.000000,LON=0.000000,FIX=0,AGE_MS=4294967295
TL_TIM,2004-01-10T00:13:54_INVALID
VWXYZ

Missing or invalid CAN values are shown with the placeholder:

0xHHHHHHHH

Valid CAN rows are sent as two 32-bit hexadecimal values:

MC1VEL,0x12345678,0x9ABCDEF0

Speed Data

The firmware keeps separate speed values for the different sources:

• imu_speed_mph: speed estimated from the IMU.
• gps_speed_mph: speed reported by the GPS module.
• can_speed_mph: speed decoded from CAN data.
• vehicle_speed_mph: the selected vehicle speed after choosing the best available source.

For the ESP32/Bluetooth CSV stream, all of these speed fields are included.

For the RS232 stream, CAN speed is not repeated in the NAV line because the raw CAN speed messages are already present in the fixed hexadecimal CAN rows, such as MC1VEL and MC2VEL. The NAV line keeps the display cleaner by showing IMU speed, GPS speed, selected vehicle speed, GPS position, and GPS fix status in one place.