I have an application where we will be controlling a door. There will be a button widget on the App side that while pressed will energize two relays(one for a valve and one for a pump). When the button is released the valve and pump need to turn off so the relays will turn off.
It is however imperative that if for some reason communication between the app and hardware break that the two relays on the board turn off. What I am thinking is sending a signal every 500 milliseconds or so while the button is pressed. The hardware will listen for these signals and will maintain the relays as long as the signal is being received. If it however does not receive the signal after 2 seconds or so it would turn the relays off.
Is this possible in some way? I don’t think monitoring BLYNK_APP_CONNECTED() would be responsive enough for this. I am open to other ideas though.