This is the simple, Arduino based, bike speedometer.
A velocity is calculated, whenever a magnet pass near a reed switch, closing the circuit. Then, speed is displayed on LCD in kilometres per hour. When the wheel is still for 2 seconds, the velocity is set to zero. Maximum measurable speed is limited by 100ms debounce time and it equals 76.68 km/s.
The script was prepared specifically for my bike, with 26 inches wheels. Double check the size of your wheels before using it.
- Arduino Micro
- LCD 8x2, based on the Hitachi HD44780
- Reed switch
- Magnet (mounted to one of the wheel's spoke)
- 10k ohm resistor
- 50k ohm potentiometer
- Toggle switch x 2
- 9V battery
- Epoxy paper protoboard
https://www.youtube.com/watch?v=Dy2b9hupqwA
Inspired by Arduino Bike Speedometer