- Remove logic that would inhibit error detection until the first value is received. This logic posed a risk when no encoder is connected at all.
- check error flag in AMS mode
- Make CUI mode work. Only tested with emulated CUI encoder.
- only go to ready-state if a successful value was received _and_ the offset was already pre-calibrated
- enable pull-up on MISO so that a disconnected AMS encoder can be detected
- update encoder documentation