AnsweredAssumed Answered

1701 Index filter missing 0 state from pulse counter

Question asked by davepmo on Mar 26, 2015
Latest reply on Mar 27, 2015 by davepmo


I'm having trouble with this index selectable filter schematic.  Bob helped me make a pulse counter that will count up to a value, and once it reaches it, the next pin toggle it starts at 0 and it counts up again, and is reset via another pin. The counter works, as does the reset.


I hooked it to an index selectable filter.  The filter works, toggling through the different filters associated with the index.  But when the counter reaches it's terminal count and goes to 0 on the next pin toggle, the index filter stays on the last one (filter 4 in this example).  If I toggle again (to 1) it then goes to filter 1 and behaves normally until it starts at 0 again.  It always skips the 0 filter unless I reset it.


I think there is some funky timing thing going on, but I can't capture it with the readback function, the counter looks good.

I'm testing this with the 1701EZ board with white noise on the input and a spectrum analyzer on the output, so I can see the filters as they change..


I'd love some debug advice on how to fix this. 

thanks a lot,