Imported from GitHub: Kleptobot/bike_telemetry · commit 1d11876 · license MIT

Description

open source bike telemetry project using an nrf58240

README

OBike — Open Bicycle Telemetry Platform

OBike is an open-source hardware and firmware project for bicycle telemetry and logging. This repository contains everything needed to build, program, and enclose the device: firmware source code, PCB design and schematics, and 3D CAD files for a printable enclosure.

Purpose: capture bike telemetry (speed, cadence, power, heart rate, GPS tracks, barometric altitude and sensor data), present it on a colour display, and log sessions to an SD card in TCX/CSV formats.

Standard bike peripherals that connect via Bluetooth and implement the CSC, HRM and CPS profiles are compatible.

Contents

• src/ — Firmware source (C++). Core subsystems in src/HAL, UI in src/ui, display driver in src/display, logging in src/TCXLogger.cpp.
• include/ — Public headers and shared definitions.
• kicad/ — KiCad schematic and PCB layout files (board, symbols, footprints).
• 3D_CAD/ — STEP/STL and other CAD files for 3D-printing the enclosure and mounting hardware.
• lib/ — Project-specific libraries and footprints used by the PCB and build.
• devices.txt, platformio.ini and other project metadata.

Hardware overview

• MCU: Seeed Studio XIAO nRF52840 (Sense) (nRF52840 Cortex-M4 BLE-capable MCU).
• GNSS: Quectel LC76G module (handled by the LC76G driver in src/HAL).
• Display: ST7789-based full-colour 240×320 SPI display (driver: Adafruit_ST7789, wrappers in src/display).
• Sensors: DS3231M RTC, DPS368 barometric sensor, IMU (on-chip 6DOF), SD card for logging.
• IO: 5-position momentary switch (hardware debounced, connected via I2C IO expander), Bluetooth peripheral support (CSC/HRM/CPS).

Software & features

• Firmware: PlatformIO-based build using the Arduino framework. Main application lives in src/App.*.
• Telemetry aggregation: blends readings from BLE sensors (CSC, CPS, HRM), onboard sensors and GPS to estimate speed, cadence, power, altitude.
• Logging: TCX (Garmin) and CSV track logging to microSD. Raw NMEA sentences are also optionally logged to /gpsLog.txt for debugging.
• GPS control: routines to configure NMEA message rates and send PAIR/PQTMCFG commands to the LC76G.
• UI: Simple app UI with screens in src/ui/Screens and widgets in src/ui/Widgets.
• Bluetooth: device scanning, pairing and connection management implemented in src/HAL/Bluetooth and src/Bluetooth subsystems.

Dependencies

• PlatformIO project (see platformio.ini).
• Arduino/Adafruit libraries required by the display and graphics: Adafruit_GFX, Adafruit_ST7789.
• Adafruit RTClib library
• Adafruit MCP23017 Arduino Library
• Seeed Arduino LSM6DS3 library
• XENSIV Digital Pressure Sensor library
• bblanchon/ArduinoJson
• TinyGPSPlus for parsing NMEA sentences.

Key files to inspect

• src/HAL/LC76G.cpp / src/HAL/LC76G.hpp — i2c driver for the Quectel LC76G module, NMEA assembly and PAIR command handling.
• src/display/Display.hpp / src/display/Display.cpp — ST7789 display wrapper and canvas handling (240×320 canvas, 16-bit colour buffer).
• src/TCXLogger.* — TCX formatting and SD card logging.
• kicad/ — schematic (.kicad_sch) and PCB (.kicad_pcb) files.
• 3D_CAD/ — STEP/STL files for the housing and mounting hardware.

Troubleshooting & debugging

• Serial logs: enable GPS debug via build-time DebugConfig.hpp flags to print raw NMEA and driver activity.
• Raw NMEA capture: the LC76G driver writes raw NMEA sentences to /gpsLog.txt on the SD card. Check this file for GPS traffic.
• Common problems seen during development:
  • NMEA assembly overflow: long or malformed NMEA streams previously caused buffer issues; ensure firmware is up-to-date with bounds checks in LC76G.
  • PAIR response handling: the LC76G PAIR command flow expects specific responses — check COMMANDS[] in LC76G.hpp and HAL::handlePAIRResponse if you see unexpected behavior.

Appendix — repo map (high level)

• src/ — firmware implementation
• kicad/ — PCB and schematic files
• 3D_CAD/ — mechanical CAD files