Ground Tracking LED Longboard

Building a ground sychronized, configurable LED lit longboard that creates a "floating on light" effect.

The inspiration

Early in my freshman year of undergraduate, I picked up longboarding as a fun way of quickly getting to class. One night while riding, I had the idea to create the effect of "riding on light" by synchronizing the pixel movement of LEDs on the bottom of the board to the board's speed. This project stemmed from that errant thought.

Design

To accomplish this task, a few different modules had to be designed and built. The system hinges around a custom encoder built into one of the longboard wheels. Eight neodynium magnets of alternating polarity were glued into a custom printed assembly bolted securely to the wheel. A pair of hall effect sensors can then detect the rising and falling edges of each magnet to sense both speed (based on time between detections) and direction (based on the offset between the two sensors. This information is fed into a esp8266 based microcontroller that reads the pulses and coordinates the movement of indiviudally adressable LEDs on the bottom of the board. For user control, a button is used to cycle pre-programmed light patterns, a potentiometer controls brightness, and an OLED screen shows your measured speed, chosen light pattern, and brightness.