The idea for this project comes from the light addon kits people install on sports cars. The visual effect can be quite stunning from the right angles.
Typically, the light remains constant and gives an almost floating appearance to the car so I figured the effect might look cool on a longboard.
In addition to the longboard I needed the following hardware:
- Arduino Nano Every micro-controller
- Addressable RGB LED-strips
- A Hall effect sensor
- A power switch
- Tools for soldering
An overview of the hardware can be seen in the following photos:
The hall effect sensor is mounted on the truck of the longboard and neodymium magnets are glued to the inner part of the wheel. The hall effect sensor is able to sense when a magnet passes by the sensor.
The software running on the Arduino Nano is a simple state machine for detecting if the board is moving. It does this by comparing the current time since the last time a magnet was detected by the hall effect sensor. An early test setup to test the Hall effect sensor for controlling LED animation can be seen in the following video:
If no movement is detected (No hall effect detections have been made for some time) a simple oscillation animation is playing for all the LEDs. A sample of this can be seen in the below video:
If movement is detected we sample the hall effect sensor and store the last two detections in a circular buffer with the timestamp they were detected. The current speed is then estimated using numerical differentiation of the two samples and the calculated speed is used as a gain for a rainbow-like animation where the estimated speed is proportional to the color propagation speed in the rainbow. An example of this can be seen in the following video:
Thanks for reading!