Here is the first step for part two of my cooling project. It uses just 3 outputs to drive a pair of shift registers, and ultimately a 4-digit bubble display!
Currently the display toggles between displaying 24.5C and 1496 (the RPM)… Why? Because those are the two hard coded values I’ve picked in my function calls!
Given its only 3 pins, my plan is to put it all on a different bit of Veroboard, and connect it to the original board with a plug! Exciting stuff 🙂