After reading the instructables post on the simplisafe sensor I modified the ring sensor and tried to integrate it with my wired sensors. This is what I found:
testing with a spooled wire about 20 feet worked fine
When I added the ring sensor into an actual wire run to a door I was able to register the door closing if the circuit was originally open but then after that the ring sensor would always display closed even when the door was opened
I saw the comments about adding resistors to the leads so I did that and I was able to register the door opening and closing successfully.
I then tried to add another 2 door sensors in series and the initial problem came back. So I had to add another resistor
So now I have 3 4.7k resistors and I am able to monitor 4 doors total.
But on my second zone of sensors wired in series I cannot get it to work. This zone has 5 sensors but I have also tried it with 4 and tried to wire it the same as the first.
The problem on this zone is the first 2 sensors in the series will register an open and close fine, and the last sensor will register fine, but if I open the 2 windows in the middle the ring sensor will still see it as closed.
I have searched and found a few posts of people saying that they have had success by adding a capacitor to the circuit but I am unclear on how exactly they did this. Here are all the links I have found and maybe someone else can explain this better.
- https://simplisafe.com/forum/customer-support-forum/installing-and-using-simplisafe/hard-wired-existing-door-sens#comment-604970
- https://www.reddit.com/r/Abode/comments/6ny9w9/options_for_using_hardwired_sensors/
- https://www.reddit.com/r/Abode/comments/5sclaf/connecting_hard_wired_sensors/
What these people are saying is there is AC voltage induced into the circuit and adding a capacitor somehow fixed their issue.
I don't understand why the sensors in the middle of the circuit will not register the opening of the circuit. I know this is a strange issue but maybe someone else has knowledge that will help solve this problem. If this is AC voltage from surrounding wiring how would a capacitor be wired into the series circuit to fix the problem?
I originally had this as an answer on a related post Integrate residential hardwired alarm zone with modern wireless sensor
Best Answer
Hopefully this will help someone else. I just spent three evenings working on this. Wanted to use my existing wired sensors and have all the Ring contact sensors centrally located (in the closet of the old alarm system box). Here's what I have learned:
You can attach wires across the magnetic reed switch however this only works with a very limited wire length to the existing wired contact sensor. In my experience wire lengths of less than 20 feet work although not reliably and one wired sensor would not work with a wire >2 feet.
On the Ring sensor PCB, there is a spot for a surface mount berg header. See picture (JP1):
From other posts and my own experimentation, JP1 pin outs are as follows:
In my experimentation the "C" and "O" inputs are no better than soldering a wires across the magnetic reed switch in that only very short runs to the wired contact switches work.
Best solution is to put a 1M Ohm resistor from "G" to "V" and connect the wired contact switch across "+" and "V". The 1M Ohm will minimize the battery drain (less current than what flows through the internal resistance of the battery) but provides the needed pull down to activate "Open" when the wired sensor opens. With this configuration I have wired contact sensors working reliably with >50 feet wire runs and one Ring sensor with 4 wired contact switches (my basement door and windows) connected in series.
Be careful soldering to these pads. The pads are surface mount and it is very easy to lift the pads once wires are soldered to them. Strain relief attached wires!
The "V" active input opens the door (pun intended) for a lot of other potential uses. Could be used attach/monitor an existing glass break, water or other sensor not available from Ring with some simple modifications to the other sensors.
Enjoy and good luck!