CrossRoads:
Why did you start a whole new thread on this keyboard?
To pose appropriate questions in appropriate forum.
Sensor question in sensor, multiplexing in multiplexing, audio in audio etc.
It is the same project which has different aspects to it.
It is is moreappropriate I can ask All the questions in a single thread, but then we will have audio, multiplexing, programming, sensor etc. In a single thread in which most of the questions will not be pertinent.
It's kind of like when a patient comes to see me for an eye problem, a dermatologist for a skin problem and an OBGYN for, well, another problem 
even if it's the same individual.
Also, while we are on the topic (forgive the pun) i found interesting partial answers to my questions in older posts, but they were closed so i could not follow up with questions or comments. Why close old topics? Most of them are relevant with current devices.