Change of state as trigger for Digital Input


#1

Hi folks,

When we setup a trigger based on a GPI input, its either ON or OFF.In some cases it would be interesting to use a Change of state as a trigger, explanation :

For example I want to turn on a light with both a real life switch and cayenne, my real life switch will trigger a GPI on my board. Then, i set a trigger to rise the appropriate GPO for my relay to turn on my light. Likewise, I can just activate my GPO in cayenne and lights goes up, but my real life button will not move.

But if i turn on my light IRL, and off with cayenne, my real life switcher is still up, so I have to make the switch down and up to start the light again. Or if i could make a trigger that is set to Change of State instead of ON or OFF, I just flip the switch once and bob is your uncle ! Cleaner and prettier way !

(would also be possible to make this happen inside the board, without using cayenne, but thats sneakier)

What do you think ?


#2

There are two ways to do it. You can replace the switch entirely with a cayenne controlled switch, which is the easiest option but might look bad (sounds like what you were suggesting), or you can rewire the light as a 3 way switch and have the relay and switch both work.


#3

Hi, thanks for the reply.

I was using my light switch as an example, indeed it’s not pretty and I thought about your way already and it’s indeed a better way, and more “immediate” (when you flip the physical switch the light turns on immediately)
But, sure there’s more applications to “change of state” trigger, I work in TV and we use GPI a lot and we use “change of state” triggers all the time.