I’m looking for a trigger switch, basically something which when an electrical current passes through, will trigger a signal to the hub. Like a motion detector but instead of the motion sensor triggering the signal it will be a simple current zap.
Since there are no driveway sensors on the market yet want to build my own. I’ll use an optical eye which when cut will trigger a relay which will send a current to that trigger switch.
Many people simply use a z-wave Magnetic Contact Sensor with external contacts. You simply need to close/open those contacts electrically (e.g. via dry contact relay) to change the state from Open to Closed. (i.e. don’t use the magnetic switch portion of the sensor, just the external contacts.)
No need to “monitor current flow” as that is much more complicated that simply opening or closing a set of contacts.
Here is an example where someone used one of these sensors to create a water leak sensor, as an example of what is possible.
maybe i’m missing something, but why do you need the 3 volt magnetic door sensor? you would just wire the NO or NC to a door sensor or dry contact sensor that has external inputs. Then pair that sensor to SmartThings.
I think a flood detector might be even easier to work with. All I need to do is making contact between the two electrodes. Unless they require a “permanent” contact rather than a short close/open trigger.