I recently tried to use this:
http://arduinoprojects101.com/arduino-rpm-counter-tachometer/
But it doesn't seem to be working.
I used the Infrared Emitter and Detector from Radioshack:
would that be an issue?
Any suggestions?
The radioshack components are a normal IR led and a normal IR transistor. So that should work.
Are you sure everything is connected as in the picture ?
Are you sure its emitting light? You can test this easily with a camera.