This thread is more like a survey as to how you organize your variables in a big program.

My concern is about the waste of variables used all over the program one writes.

I saw the problem mainly in large code with interrupts. If one wants to use a variable inside the interrupt, this must be new. But, if for every task we assign a new variable, at the end we may have a lots that are really not necessary and most of them used once.

In C threre are local variables so there is no waste in memory.

How do you organize your programs in respect of this matter?

Ioannis