This project is a dual fan speed controller designed to change fan speed based on the speed of a bluetooth speed sensor or smart trainer. It is based on two modules, a mains triac controller and a nRF52840 SOC system.
The firmware is licensed with the MIT license and was build using platform IO. The nRF52840 module is an Adafruit Feather nRF52840 Express and a big kudos to Adafruit and all the work they do for open hardware.
I got the idea from Keith Wakeham's Blog. Thanks to Keith for the interesting blog on bicycle related tech.