Regarding the suggestion of using a seperate thread, why should I do that? Is a sleep based control more precise, than a timer based control? My guts say that it isn't, because you never now when a thread will be woken up again and it might have slept too long.

I think the trade off between having a faster timer and the complication plus windows dependency of the code is not worth it for me. I can live with 16 ms as long as the rhythm is steady. The most important criterion is that every iteration should take an equal amount of time.

So the question that hasn't been addressed yet is, how precise are the timings that I get from QTime? When it says 16 ms, has it really been 16 ms? Or something between 10 and 20?