A simple mini-map based on an ESP32C3 for cycling. Renders a map based on the current position and optionally overlays a GPX-track. Featuring OSM-based offline maps with multi-constellation GNSS-positioning and GPX-track rendering.
DISCLAIMER: This is a hobby project which lacks documentation, clean code and unit tests.
Even though the GIF is low-framerate, the ESP can easily render the map at 60 FPS if the currently shown part of the map isn't too busy.
The motivation behind this project was to create a cheap (~50€) device that displays a komoot gpx track as an overlay over a map for cycling. It has to work without a smartphone, be readable in direct sunlight and last a couple of hours in terms of battery.
hardware Contains instructions/sources/files to build the physical device
software Software to convert maps, view exported maps and the embedded code for the ESP
software/cpp Tool to convert OSM maps to an optimized format for the ESP
software/python Utilities to inspect converted maps and/or get familiar with the map layout
software/esp32 Firmware for the ESP32
A wiring diagram, sourcing-list and a .STEP file of the whole assembly can be found in the hardware folder. Please refer to the STEP file for assembling the device.
For the 3D-Printed parts (hardware/STL), I recommend the following print settings:
| Settings | Value |
|---|---|
| Wall count | 4 |
| Top/Bottom Layers | 4 |
| Layer Height | 0.2mm |
| Material | ABS/ASA |
| Infill | 40% |
| Support | Yes |
My device is printed out of PLA+ but ASA/ABS is the better choice for this application.
Follow the instructions in software/cpp/README.MD to compile the conversion tool and create a map binary.
- Format the SD-Card as FAT32.
- Place the map as map.bin in the root folder of the SD-Card
- (Optional) Place the GPX-track as track.gpx in the root folder of the SD-Card
- Install Visual Studio Code
- Install the Platform.io extension for Visual Studio Code
- Open the Platform.io project software/esp32/esp32c3-bike-companion-32
- Have a look at the main.cpp. You may need to fix a bug in one of the libraries for the SDCard-Reader.
- Connect your Seeed ESP32C3 to your PC
- Flash the firmware
All you need to do is mount the device to your bike and connect it to a power source.
The device will automatically power on. It does a small self check on boot and then enters fixing mode, where it remains until it receives a valid position fix from the GNSS module. The map with the current position is only rendered if there is a valid position fix, otherwise it will show "Fixing...".
If the device encounters an issue during boot (e.g. one component shows ER), check the serial monitor for log messages.
The 3D-models for the ESP32C3 are from GrabCAD:
| Model | Author | Link |
|---|---|---|
| ESP32C3 | Maurice Pannard | Source |