I have a rain sensor that sends an input signal to my Cloudbit, which then sends me a notification (using an IFTTT recipe) when it starts raining. The problem is that the rain/moisture sensor remains constantly ON when it gets wet, so I continue to get notifications from IFTTT every minute after it gets wet.
I would like to just get a single notification when it starts and stops raining (i.e. when it changes state). Another example would be if you used the bend sensor to be notified when a door opens or closes. You may not want to be continuously notified when the door remains open, only when it first opens and/or closes.
I’ve tried using the timeout bit to shut off the high signal after a certain duration, but that doesn’t work. The constantly high input signal overrides the timeout bit. I tested this using a simple pushbutton circuit. If the pushbutton remains depressed, the signal remains ON beyond the timeout bit until the pushbutton is released.
For a different project, I created a one-shot pulse module, but that sends a pulse when the circuit is initially powered on ( http://littlebits.cc/projects/delayed-one-shot-pulse-timer-module ). In this new situation, I’d like a singe pulse when the input trigger goes high (and stays high) so I only get one notification from IFTTT.