[hw640] has put together a well written and detail packed explanation of how to interface with a digital rotary switch. These digital opto encoders have just two outputs with four possible logic le… ...

The switch offers continuous rotation through 30 positions per revolution. Operation is from 4.5 to 7V (5V nominal) and consumption is 150 – 350mA. It is available with either UART or MIPI interface, ...