Re: [PIC] debouncing in c by Scott Dattalo .

David P Harris wrote: > Wouter van Ooijen wrote: > > >>>I am looking for an example to debounce several push buttons >>>in c. While >>>debouncing the micro shouldnÂ´t be blocked by a timer. >>> >>> >> >>Easy method: check the buttons only each xxx ms. xxx must be longer than the bounce time. When unknown xxx = 50 ms is a good guess. >> >>Wouter van Ooijen >> >> > > You know this is dead simple, and I cannot think of any criticism of > it. Nobody has commented otherwise, have they? Well, no one's commented on it because the thread has only been alive for a day or so. N*6 months ago when we last talked about this thread, the same group of people chimed in as this time and this same point was discussed (maybe it was discussed for N being even)! But Wouter's method is more than sufficient for most cases - if the switch isn't bouncing, then you can reliably read its state without having to resort to elaborate filtering. My debouncing routine has its roots in RTU relay time tagging; a environment far different than a snap dome. But, there are at least two reasons why you might want a debouncer/filter: 1) faster response 2) remove "spurious" transitions. Both of these are probably insufficient reasons for normal switches. If a switch can be pressed at a rate faster than it bounces, then it will suffer from usability issues. If there are chances for spurious transitions then there again usability issues.