@Rongzhong Li Thank you, Nybble is now partially alive. All optimizations as mentioned in post Root cause analyse on strange FTDI232 / NyBoard behaviour and finally correct type of batterie really helped a lot. Calibration was now working and Nybble became partially alive.
Now there is only one strange behaviour left which is hard to describe. I installed Nybble.ino and I could perform most commands via IR.
But for example in BALANCE mode I detect the board making a beep noise and movement partially interupts, but within a second calibrates back to correct position.
Or in WALK mode the movement is interupted almost every second with a short stop and beep (as cat needs to have a short rest).
Any idea why this happens.
@Mr Robot & Rongzhong Li ; what exactly is function of that "extra capacitor in parallel with C3 (or the power line of any servo)." and how is it working? What type of capacitor did you use?