It doesn't make a difference to the triggering of the board. The playback is triggered by a momentary shorting of the two pins. Just make sure that there is no voltage going to the trigger pins on the ST board - you'll fry the ISD chip. The only time polarity matters is if you are using the same relay to handle a low voltage power source. Example: 12VDC wall wart connected to the Common and NC side, ST board connected to the Common and NO side. Then the negative of the power supply must be connected to the Common pin of the relay and you have to experiment to find the "negative" of the ST board and connect that to the Common pin of the relay. If you don't wire it properly, the ST board is subject to false triggering.
OK, follow up. I'm connecting the trigger wire to the OUT5 and GND of the Prop-1. Is this considered 'sending voltage' to the trigger pins on the ST board? Sorry for what may be an obvious answer but I'm coming in with almost no experience in electronics.
Do those pins correspond to pins on a relay? If they do, then you won't be sending any voltage to the board's trigger pins. Do you have a way to activate that switch and check for yoltage across the pins? If anyone else wants to chime in on this thread, feel free.
DW, you can do like your wanting.... You dont need a relay. Polarity doesnt matter on the trigger. Just make certain you have a common ground. Re-read Jon's post a few times and hook up like he says. There is no voltage on the pin when floating/to ground and trigger is 3or4 mSec...it just completes/closes the circuit.
OK so wiring my boards together as shown in Jon's picture is the right way to go even though I'm using a Scary Terry board and not the one he shows for demonstration? And I don't run a wire for voltage from the Prop-1 to the ST board as shown since the ST board has it's own power?
Cow doesnt give much info but says the new board comes with a 4 battery connector or use your own wall wart. This (and the pic of the STB) tells me that the power connection to the STB is still to the blue terminal blocks in the same manner as in Jon's picture. You can still power your STB from the prop1.
The key to the prop1 triggering the STB is that both boards have a common ground.
Thanks guys! With you and Jon from EFX helping me tonight I've got it up and running. The program still needs some tweaks but the triggering is working. It seemed like a simple question but I neglected to explain my set-up thoroughly (the STB has it's own power supply). I followed Jon's picture as posted above and left off the line running from V to the + on the STB. All works well except for some retriggering and delayed triggering. If anybody is a whiz on the Prop-1 I can post code here and maybe you can help? I've posted on EFX and hoping Jon will check it out and reply.