Telemetry Node

Real-time embedded telemetry logger: ESP32 + FreeRTOS samples IMU, temperature, and battery voltage at a fixed rate and streams binary frames over UART. A Python host tool decodes the stream and writes CSV.

Resume bullet: Designed and implemented a real-time telemetry logger (ESP32, FreeRTOS) with fixed-rate multi-sensor sampling, CRC-protected binary protocol, and Python decode/export tooling.

Hardware

• ESP32 dev board (for example ESP32-WROOM-32)
• MPU6050 IMU (I2C, 3.3 V)
• Optional battery divider to ADC pin
• ESP32 internal temperature sensor

Wiring

ESP32	MPU6050
GPIO 21 (SDA)	SDA
GPIO 22 (SCL)	SCL
3.3 V	VCC
GND	GND

Battery (optional): divider to GPIO 34 (ADC1_6). Update pin config in firmware/src/config.h if needed.

Firmware

cd firmware
pio run
pio run -t upload

UART defaults to 115200 8N1.

Host Tool

cd host
.\setup_venv.ps1
.\run_test.ps1
.\.venv\Scripts\python.exe decode_telemetry.py --port COM3 --out data.csv

Linux/macOS serial examples:

python decode_telemetry.py --port /dev/ttyUSB0 --out data.csv
python decode_telemetry.py --port /dev/ttyACM0 --out data.csv

Protocol

Frame format:

• Sync: 0xAA 0x55
• Length: 1 byte (payload length = 20)
• Payload: timestamp + accel/gyro/temp/vbat fields
• CRC16: 2 bytes little-endian over payload bytes

See docs/protocol.md for full layout and deterministic fixture bytes used in host tests.

Verification

1. Host protocol checks (no hardware):
   • python -m unittest discover -s host/tests -p "test_*.py"
   • python -m ruff check host
2. Firmware + host stream:
   • Flash firmware, then run decoder with your serial port.
   • Confirm CSV rows arrive around the configured sample interval.

CI

GitHub Actions runs:

• ESP32 firmware build via PlatformIO
• Host dependency install
• Host static check (ruff)
• Host protocol tests (unittest)

License

MIT