GPS Bicycle Computer w/ ESP32, Speedometer, SD Logging

ESP32 (Arduino) Based Bicycle Computer with GPS and SD logging

This is still work in progress but mostly functional this far.

The code and mechanical aspects of the project definitely work well enough for a daily usage scenario. *Documentation isn’t available yet, I’d recommend anyone to start this project who already has a decent understanding of electronics.

See the code for pin-definitions and / refer to the schematic in the pcb folder on GitHub*

Quick overview:

• GPS Speedometer and other data such as altitude, traveled distance and time
• 128x64 LCD
• RTC DS3231
• Temperature and Humidity Sensor HTU21D
• LDR for backlight adjustment
• Micro SD for logging your trips
• Charging over Qi Wireless charging
• One user-button
• 2x 14500 LiFePO4 Battery

Print the necessary files and build the circuit.

Initially I planned for the unit to be recharged wirelessly by the bicycles dynamo generator. At least on my particular bike the output power was no where high enough. So I had to recharge the unit at home using a wireless charger powered by 5V. Keep that in mind when printing the files.

For prototyping I recommend to use a small breakout-board for the ESP32: https://www.aliexpress.com/item/32972157302.html

This is the LCD I used: https://www.aliexpress.com/item/32956038705.html

LiFePO4 Protection Board: https://www.ebay.de/itm/12A-1S-3-2V-LiFePO4-Lithium-Iron-Phosphate-Battery-Input-Ouput-Protection-Board/263309495883

Push Button Power Switch Board: https://www.ebay.de/itm/6A-Flip-Flop-Latch-Switch-Module-Bistable-Self-locking-Trigger-Board-LED-Motor/282381541189 alternative: https://www.aliexpress.com/item/32796080209.html

Qi Receiver Pad: https://www.aliexpress.com/item/32933478038.html

GPS: https://www.aliexpress.com/item/1872389528.html

Please note that the PCBs are still work in progress and contain errors.

More info on my website: https://wizeus.de/

See GitHub for the Code and other information: https://github.com/wilhelmzeuschner/esp32_gps_bicycle_computer

Print Settings

Printer:

Tronxy X8

Rafts:

Supports:

No

Resolution:

Infill:

=15%

How I Designed This

Fusion 360