Alden Hart Riley Porter Normally open (NO) probe is being used by folks for

Controllers g2core and TinyG
1

@Alden_Hart @Riley_Porter_ril3y Normally open (NO) probe is being used by folks for PCB probing. This means that the microcontroller input is at all times in HIGH (logical 1) state except when the probe closes the circuit which results in LOW (logical 0) for a very short period of time. That means ‘1’->‘0’ transition, which is the TRAILING edge. So, will this ever be true for NO probe if we check for LEADING edge (code from TinyG2/gpio.cpp)?

if (in->probing_mode) {
if (in->edge == INPUT_EDGE_LEADING) { // we only want the leading edge to fire
en_take_encoder_snapshot();
cm_start_hold();
}
return;
}

2

Maybe it’s better you create an issue here? https://github.com/synthetos/TinyG/issues

3

Still working on it before creating a support ticket :wink:

4

@sszafran Actually, https://github.com/synthetos/g2/issues might be the better place, given that you are working in G2 space.

We may need a PhD Linguist to help us here, but I don’t think I would necessarily agree with your interpretation. To my thinking, the leading edge of a random event is when the state transitions from the ‘normal’ state to the ‘event’ state. Or, in binary terms, if the Normal state of a NO switch is 1, then the 1 to 0 transition would be the leading edge of the event, the event duration is the time at 0 state.
A lot here open to interpretation and input from the developers who implemented.