Hi Guys,

Henrik:
I am checking for break in continuity due to physical movement. My idea is to use weak pull-ups on one side of the data line and ground the other side. Any break in the line would cause a leading edge interrupt.
Due to the mechanical nature of the test, any line could fail irrespective of the other lines. The test period is around 1 minute.
The failure mode could be intermittent (ie momentary break in continuity) or permanent.
The tests are more indicative than quantitative in that I want to know if one (or more) data lines are broken more often than others - the actual count does not need to be specifically accurate.
Ideally there would be no failures during the test but hey, who lives in an ideal world? I has assigned WORD variables to all nine counters - just in case!

Amoque:
I am not sure how a snapshot would work considering any one of the nine data lines can generate the interrupt. What are you proposing?

Cheers
Barry
VK2XBP