Shared Projects by jamesotron

I needed to control a handful of 4-pin fans. Flash with the accompanying firmware to have USB CDC-based control of all four connected fans as well as the on board RGB LED and temperature sensor. Fans are controllable via both duty cycle or RPM (with tuneable PID controller). There is a solder jumper to connect the 5V USB supply to the fan’s VCC pins as long as you stay within USB’s 500mAh budget, else you can connect and external supply to the screw terminals. This is deliberately the cheapest way I could think of to make this device, thus the through hole components (I’m just using the parts laying around on my bench). I got 10 knock off RP2040-Zero boards from AliExpress for about $2 each.

A really tiny board for breadboarding ATtiny 87 AVRs - my new favourite micro!