This rotary encoder kit can be used for sensing motor's position and velocity. It is a very simple kit consisted of an optical beam sensor (opto switch, phototransistor) and a piece of slotted disc. It can be connected to any microcontroller via the 3-pin header. The optical beam sensor detects missing slots of the slotted disc, and generates a pulse train.
It requires +5VDC to power up, and gives a 0V and 5V output. It provides a 5V output when the beam is blocked, and a 0V output when the beam is unblocked. Your microcontroller can simply read the 0-5-0V pulse train to determine how far your motor has traveled, and how fast.
The kit includes a green LED that light up when the beam is uninterrupted.
Specification: