Here is an alternative multipurpose Visonic Door/Window Sensors Device Handler. There is a discussion thread about this sensor here
I was originally posting this DTH in the thread, but someone suggested I should start a new thread to make it easier for comment and searching. So here we go.
With some modifications, the sensor can be used as
smoke detector (for wired smoke alarm)
tilt sensor to use for mailbox sensor or garage door sensor
Since they are only $10 a pieces, I can afford to put the modified leak sensors in every room which may have water problem in my house. Comparing spending like $30 a piece for a real water sensor in the market.
And if you already have a wired smoke alarm system, you can connect them to the visonic sensor and report status back to smartthings. You don’t need to replace them with smart smoke alarm just for that purpose.
And here is the screenshot when it is being use as different sensor function
After the modification, the two exposed wires will be open under normal condition. When the two exposed wires make contact to water, since water will conduct electricity, the water will connect the two wires like closing a contact. Once the sensor detect the wires are connected, it will trigger an event to smartthings and alert you there is an water leak thru the device handler.
I think he is talking about conductivity of metal versus conductivity of water. It is the measure of how easy electricity can pass thru an item. For metal is about 50 while for water it is about 1, so there is an order of magnitude different, but still it is good enough for the sensor to detect the two pieces of metal are connected together.
Thanks, @pakmanwg, this was fun and it will be useful.
One thing to note for folks doing this - the part of the wire you cut through is actually enclosed in a tiny bit of glass, so you’ll want to cut it where you can catch the small broken bits that will fall off. then I used some needle-nose pliers to “crunch” any remaining glass bits off the wires. Very easy to do.
The sensor has it own power, so I just solder the two exposed wire to the normally open and the common end of the relay. It may be easier if you solder two long wires to the sensor and then use wire nut to connect the two long wires to the relay.
On the other side of the relay, you need to figure out how your alarm is connected and connect the three wires to your alarm.
Everything is wired up and working as expected with ST however I’m having an issue with Actiontiles. The clear state looks normal but when smoke is dectected, the tile does not light up and the icon changes to a “?” with the word smoke below it. Any ideas how to correct?