Prop-1 negative pulse trigger

[JackMan]

I'm trying to get a Prop-1 to trigger with a 16ms negative pulse on PIN6. I have the setup jumper UP and the trigger wire on W. The Prop-1 triggers on power up and then keeps re-triggering, even with the trigger wire disconnected. Does the trigger code need to be different than what is typically used?

[JonnyMac]

Yes, it does.  Is this an open-collector output that will pull the line low?  If yes, move the SETUP jumper to UP, clip the ULN pin (so it doesn't *fight* with the SETUP pull-up) and try this code:

Main:
  timer = 0

Trigger_Check:
  PAUSE 1
  IF Trigger = 1 THEN Main
  timer = timer + 1
  IF timer < 12 THEN Trigger_Check

With active-low logic on the Prop-1 we can't use the cute, inline trick that we normally employ.  There are other ways, but I think what's above is the easiest to follow.

[JonnyMac]

BTW, for an active-low signal you need to use the white and black wires; if N.O. type switch it doesn't matter which connects to what, for an open-collector output you need to connect the black wire to ground on the other side, white to the collector of the circuit.

[JackMan]

Thanks Jon, that did it. I only need P6/W, it's connected to the collector of a transitor.