Averaging AtoD samples

[HankMcSpank]

Mabe I'm missing part of your challenge.
How many samples will you throw before deciding it's a real change?
If you look at the filter I added you can set the # of samples to skip as well as the % above and % below to determine what level of input is out of range.

I would prob work on the spurious signal issue. good data acquisition is critical if the program is to be robust. That routine I added is really for a failed sensor check, rather than a continuous filter.

The challenge is that when detecting frequency using the internal PIC comparators......the resulkting count appears to be jittery. By that I mean for say 1Khz, you get 'counts' arriving like thus...

5000, 4999, 5000,4999, 5001, 5000, 4999,5001,3479, 5000,4999,5001


now for the life of me I can't get to the bottom of why the spurious count arrives! (which would be the preferred option), so I'm faced with getting rid of it in software. What Melanie's number sort routine does, is sort an array of samples into numerical order (which will put the spurious count at the beginning), and then averages only the middle of the array. It gets rid of the spurious count completely.

If the frequency changes, then the middle of the array (after sorting) should reflect the count.

So my challenge if you like, is to get rid of spurious counts (ie not 'average' with them at all) ...and also to do this as quickly as possible.

As I say Melanie's routine works....but I'm always open to other methods to rid spurious readings from the equation.