First of all, thanks to all of you for your contribution! I really like the approach with the slotted optical switch. I should indeed have an old mouse somewhere to get the optical chopper wheel from... The shaft is quite small, 7mm diameter, so the dimensions should be fine. So I'll attach the opti...

Hey guys, I am currently working on the starting behaviour of a small DC motor with a metal shaft attached to it. The other end of the shaft is mounted in a bearing and I am looking for a convenient way to capture the rotary speed of the shaft using my RPi2. Any ideas? Ideally, I am looking for an o...