(basic wiring, pinout, and output signal) Adding Arduino to your rotary encoder. Now that your rotary encoder hardware is up and running it’s time to tell your Arduino what to do with the encoder ...

Adafruit has made an I2C interface for four rotary encoders. It comes in the form of a PCB with four footprints that accept one of the most common rotary encoder forms (Bournes PEC11 horizontal style) ...

byte enc1oldPins = 0; // will hold state of pins last time encoder was read byte enc2oldPins = 0; byte enc1newPins = 0; // will hold new encoder pin reading, to be compared with last time's pin states ...