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T-RGB Bike Computer

A bike computer built on the LilyGO T-RGB: a round 480×480 touch display, ESP32-S3 with BLE and WiFi, SD card, and a LiPo charger on board. It reads standard BLE bike sensors, shows turn-by-turn navigation and the climb ahead from your phone, logs every ride to SD card and rates the road surface with its own accelerometer.

Main screen

Main

Navigation screen

Navigation

Climb screen

Climb

Road label screen

Road labels

Settings screen

Settings

Screenshots from the device, taken during a simulated ride from Villach to Bovec. The texts on the display are German.

Features

Display -- "Rim & Ridge" UI (LVGL 8, designed in EEZ Studio) with five screens: - Main: speed (number and outer ring), cadence, heart rate with zone band, temperature, altitude, gradient, distance (ride / trip / tour / total), ride time or clock, driving state, road-quality line, status icons for WiFi, GPS fix and battery - Navigation: opens by itself before a maneuver and closes after it. Large turn arrow, distance ring, street name, next maneuver, lane guidance, roundabout exits - Climb: elevation profile of the climb ahead, coloured by gradient, with its category; opens by itself at the foot of a rated climb (doc/CLIMB.md) - Road labels: mark surface and quality by hand while riding, as ground truth for the automatic road-quality class - Settings: a hub with one page per group -- WiFi (IP address, on/off, hotspot, network setup with the display keyboard), IMU (calibration and reference ride), height (three presets, GPS, manual height or sea-level pressure, doc/HEIGHT.md), BLE devices (speed, cadence, heart rate, TrailBridge, Forumslader in the FL build: colour = connection, battery level; long press forgets a sensor so another one can pair) -- plus restart, power off, and a mark for simulator builds

Rides and statistics - One button starts a ride, pauses it ("cruise") and ends it; stops and breaks are detected from the speed - Distance, time, average and maximum speed and average cadence per ride, trip, tour and in total; averages with or without stops, breaks and cruise time (doc/design/ride-state-machine.md)

Sensors - BLE: cycling speed & cadence (CSC), heart rate, battery level of each sensor; sensors are paired once and locked to their address - I²C: BME280 (barometric altitude and gradient, temperature), BMI160 accelerometer - Forumslader hub-dynamo charger via my BLE gateway (build variant -FL)

Navigation and GPS from the Android companion app TrailBridge over BLE (protocol): - Turn-by-turn instructions from OsmAnd, or from a GPX route that TrailBridge plays itself -- then with the elevation profile for the climb screen - The phone's GPS position for the log, and its time for the clock when there is no WiFi - Tools/gpxenrich turns a plain GPX track into such a route (turn hints from BRouter)

Road quality from the BMI160 at 400 Hz: roughness class per interval, shock detection (with second peak from the rear wheel), a calibration ride on smooth asphalt, and gradient from the accelerometer as an alternative to the barometer.

Logging - Binary ride log on SD card, one session per boot in dated folders: ride data every 5 s incl. GPS, road quality per interval, every shock, manual road labels, ride states; raw accelerometer captures on demand - Debug log and raw Forumslader log (replayable on the device) - Python tools to convert logs to CSV and GPX, and a service that fetches the sessions when the bike computer shows up in the WiFi, archives them, exports GPX, syncs to Nextcloud and uploads to Komoot

Web interface (when on WiFi) - Download, replay and delete log files; live log with adjustable log levels - Ride statistics with a chart, odometer and wheel calibration - Manage BLE sensors; debug pages for sensors, accelerometer, climbs and crashes - WiFi: saved networks and their priority, hotspot settings (doc/WIFI.md) - Firmware and filesystem update over the air

Serial console with line editing, history and Tab completion (doc/DEBUG.md).

For development: a simulator build with fake sensors (doc/SIMULATOR.md), screenshots and touch input over HTTP (Tools/uishot.py), host tests for the pure algorithms (test/, Tools/tests/).

Hardware

  • LilyGO T-RGB (the two builds differ in the touch controller variant, TRGB_ROUND / TRGB_OVAL, and in Forumslader support)
  • Optional: BME280 and BMI160 on the I²C bus
  • LiPo battery
  • 3D-printed case and handlebar mounts -- a parametric model for the Canyon CP0007 gravel cockpit is in cad/

T-RGB Bike Computer on the handlebar (older UI)

Build

PlatformIO, Arduino framework (pioarduino platform):

pio run -e trgb-esp32-s3 -t upload        # default: BLE + I²C sensors
pio run -e trgb-esp32-s3-FL -t upload     # Forumslader variant
pio run -e trgb-esp32-s3 -t uploadfs      # web interface files (data/site)

trgb-esp32-s3-ota and trgb-esp32-s3-FL-ota are the same builds, uploaded over WiFi to the device's /update endpoint. Target is TRGB-BC.local; if mDNS doesn't resolve, pass the IP: pio run -e trgb-esp32-s3-ota -t upload --upload-port 192.168.x.y. trgb-esp32-s3-sim is the simulator build.

The build applies small patches to two libraries (apply_patches.py), which needs the patch tool.

Where to go next

Source code: github.com/euphi/TRGB-BikeComputer. Contributions are welcome, see the roadmap for where help is wanted.

Licences and attributions