I just don't think that understanding exactly how the Firmata sketch accomplishes a digitalRead() is necessary in order to alter a GUI that runs on another computer.
Yes sure I agree with you, surely no necessary to understand exactly how the Firmata sketch accomplishes a digitalReadl() in order to alter a GUI...So what you mean, I should do try and error?
If you look at the code, I can not put it here coz it is too long,
The sketch doesn't even declare TOTAL_PINS, but it runs well, what happen?
Then can it mean that it is valid for arduino mega and uno which has different amount of pins?