https://www.google.com/search?q=encoders+in+arduino&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari

Rotary encoder increment prograppr by digi-key

https://www.digikey.com/products/en?keywords=cui%20inc%20amt102-v

Motor and encoder test program

https://forum.arduino.cc/index.php?topic=18274.0