Anyone worked out a method for connecting Encoder via ADC?

[Mike - K8LH]

Just wondering if anyone has worked out a method for connecting a rotary encoder + switch to a microcontroller using an ADC input? The encoder A & B switches have a common pin and so I'm trying to figure out how to connect with resistors to the ADC input so that I can determine all four encoder phases?

Cheerful regards, Mike

 

[rjenkinsgb]

Use three different power-of-two resistors to connect from the ADC to the A, B and switch contacts.
Use the low value, or something near that, again as a pull-up from ADC to V+
(Other side of all switches to 0V).

That will give you eight different voltages depending on the quadrature and switch state.

eg. 1K, 2K, 4K to A, B and switch plus another 1K to V+.