Quote Originally Posted by jessey
Will temperature become a problem with this set up,
I wouldn't think so. You've got a pretty big margin of error with that routine.

Looking at Figures 15-37 thru 15-40 of the 16F688 datasheet, it looks like there's only a +/- 3% change in freq across the -40 to +125°C range.

So the 1500ms will be 1455-1545ms, and 2500ms will be 2425-2575ms.

Since the receive loop is timed by a 100ms pause, the count will only change by +/-1, across the whole temperature range.

I think I would add a minimum though. If it only gets a count of 1 or 2 then it's just spurious noise and should be rejected.

HTH,