ash

we know. it says so in the specs

well, went on site yesterday to test and it was terrible. triggered once or a few time then nothing!!!

oh and even used the onboard switch too and that was flaky

Ended up having to write my interrruptPort class in the end and it was stable.

no i added it to see if it would fix it but alias not.

Thanks for your help but im getting no where

just attached an NP v1 and works with no false triggering.

My input stage is simple : a connector (input from outside world, open collector source) ->  pull-up resisitor -> connector (micro switch but for testing, the connectors are shorted) -> Schmitt inverter input -> Netduino input! (D0).

I added the trigger inverter yesterday.

like i said if i connect the ground from either by meter or scope it triggers!