Modify $15 SimpliSafe Entry Sensor As a Wired Switch

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Introduction: Modify $15 SimpliSafe Entry Sensor As a Wired Switch

The SimpliSafe (SS) security system consists of a wireless hub controller and a number of battery-powered wireless sensors, all communicating over a Z-wave network. One sensor in particular is very inexpensive, the $15 "Entry Sensor" wireless magnetic switch. The sensor consists of the sensor module and an external magnet, which triggers a normally-closed magnetic reed switch inside the sensor module. You stick the sensor on a door or window frame, and the magnet on the door or window itself, and as long as the distance between them is an inch or so or less the switch remains closed.

Alas, there is no provision for attaching a wired dry-contact switch. Having this module include wired switch contacts would be a boon to SS customers. You could implement a wireless doorbell, attach existing magnetic, motion and smoke detectors to the SS system, and create multiple-position sensors (to permit a closed and half-open window, but not a full-open one, for example).

Modifying the SS Entry Sensor turns out to be pretty easy. The first one took me a while, to best determine wire routing outside the sensor module, so I've documented the process in this instructable.

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Step 1: Step 1: Open the Sensor Module and Remove the Circuit Board

This takes a knack the first time you do it. There are two covers on the back of the module. The first one simply slides off, and covers the battery compartment. It also has a 3M adhesive strip fastened to it. Remove this cover and take out the battery if installed.

Next you have to remove the inner cover. You do this by prying at the three latch indentations with a flat blade screwdriver. This took me a few tries before I figures out this technique: use a large flat-blade screwdriver and pry it in toward the center of the module. Each corner should pop out in turn. You then have to fiddle with it a little to get it out the rest of the way.

Before you can remove the circuit board you have to pull out the battery contacts. Start with the contact on the long wire, at the end of the module. Use a needle-nose pliers and wiggle the contact back and forth to work it out. It's just a friction fit. As soon as this contact is out, the circuit board will become free at one end.

Use the same technique on the mid-case battery contact. Once it is out, you can gently pull out the circuit board. My board had holes for screws, but no screws were installed, so it was entirely friction-fitted. Some might have screws, however, so check for those and remove them if necessary.

The bare board appears in the picture above. The thin glass tube is the magnetic reed switch, and the metal hoop on the bottom of the board is the Z-wave antenna. Take care not to bend the LED leads, as the LED must line up with its exterior opening during reassembly.

Set the board aside for a minute and proceed to the next step, modifying the case to provide a wiring path.

Step 2: Step 2. Cut Two Notches for Wiring Path

You need to make two notches through which you'll route the wires outside the module case. The first notch goes in the inner cover, marked in red in the photo above. Simply clip out a small notch with a diagonal cutter and pull out the plastic with needle-nose pliers.

Make a similar notch in the module outer case right at the end of the module serial number, also marked in red in the photo above. Take care not to obliterate the serial number label.

Head on to Step 3.

Step 3: Step 3: Prepare Wires for Soldering to Magnetic Reed Switch

I used a single twisted pair from an ordinary solid-core Cat-5 Ethernet cable (commonly called "riser cable"). You could use stranded wire as well, although attaching is a bit trickier. Solid copper wire stays where you put it, making assembly easy.

Start by measuring a length of twisted pair (I recommend at least a foot) and then cutting the two strands in an offset as shown in the first picture above. Then strip the wire and loop each piece around a lead wire on opposite sides of the magnetic switch. You'll solder these in the next step, so a strong mechanical connection isn't needed. Route the wires along the board toward the right-hand end (with the battery cutout on the left).

IMPORTANT NOTE (9/16/2016) ! Several people have emailed me indicating that they have cut the leads to the magnetic reed switch, or what they thought was the reed switch. You don't need to do this, and I suspect you might cause problems. One person misidentified the antenna hoop (the large-gauge silver wire U on the same side of the board as the LED) as the magnetic read switch and soldered their external relay to that. Needless to say, that won't work either. The reed switch is the glass tube on the top side of the board with all the other parts. DO NOT REMOVE IT.

Proceed to Step 4, soldering.

Step 4: Step 4: Solder the Connetions and Re-install the Board

This is a very basic soldering task. The magnetic switch is not very heat sensitive, so no heat sink is necessary. Just apply the minimum amount of solder necessary for a good mechanical connection. Take care not to melt the rubber pads on the board, which seem to provide cushioning.

You're now ready to reinstall the board. This is the reverse of the dis-assembly process: install the mid-case battery connector, seat the board, and finally install the end-case battery connector.

Seating the board requires one trick: lining up the LED with it's opening in the plastic housing. I've done a number of these mods now, and the easiest way for me is to have a light behind the module so that it shines through the LED hole, then line up the LED so that it starts into the hole before you get the board fully seated.

Note that if you do the board re-seating before installing the mid-case battery connector, you'll have to start over. The wire on the mid-case connector is too short to install it once the board is fully seated.

Step 5 is to test the module before you get it all reassembled.

Step 5: Step 5: Test the Module Before Final Assembly

Test by reinserting the battery and waiting a minute for the module to sync with the SS hub. The LED flashes a couple of times once this happens. Then test the module with the magnet, just to make sure the magnetic switch still works. The SS hub should emit a chime when you open the switch by removing the magnet. Now repeat that test using the wires: short them together, then separate them. The chime should sound.

If either test fails, investigate. I has one instance where the wire I was attaching had a break under the insulation. It's a lot easier to fix that now than after everything is reassembled.

Step 6: Step 6: Replace the Module Covers With Wires Routed Outside

Replacing the covers is straightforward. First insert the inner cover, sliding the side with two latches under their tabs first by angling the board in, then pressing the board down on the third latch. Make sure the wire is routed through the notch you cut earlier.

Then route the wire through the second notch and replace the battery cover by sliding it on. The module is now ready to use. It might be a good idea to run one more test before you put it into operation.

Attach the wires any kind of dry contact switch, such as a traditional normally-open doorbell button. When
the button is pushed and released, the SS chime will sound. Never connect the module to any kind of wires that already have power on them, as the module itself is already supplying power to the magnetic reed switch. Any external power is likely to destroy the SS sensor electronics.

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58 Discussions

0
JosephS380
JosephS380

Question 2 months ago on Step 6

Using this method can I add a round 3/8" recessed door contact and use that in place of the magnet that comes with the sensor?

0
BigEHead
BigEHead

5 months ago

I found someone who soldered a 1M resistor onto the board from this link: https://electronics.stackexchange.com/questions/42...

Has anyone been able to try that? I tried it but the ring sensor was in a weird state. i had to desolder everything and luckily i was able to get the sensor to act normal. Anyone else try without using the C or the O?

0
BigEHead
BigEHead

Reply 5 months ago

BTW, i got it to work without using the C or the O. Thanks to Dave Steiner who posted it up there. It works great!

For anyone else who is going to do this, remove the sensor from ring before modifying it. I had mine originally across the reed switch and then changed it but ring detected the sensor as unknown state. i think the change in resistance may have messed with it. After removing it completely from the system, then readding it, it worked with my wired sensors. I'm excited to do more!

0
lcpr123
lcpr123

10 months ago

Here is my experience with a Ring 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-604970https://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?

0
mark-k
mark-k

Reply 9 months ago

I recently bought a Ring Security system, and had issues getting ANY of my wired sensors to register. I figured it might have been AC/DC interference, impedance issues, etc. at the end of the day I think it had to do with what the Ring was using to detect open/closed circuits, a long wire, and differing reed switches. I could short the two ends of the reed switch to force a open/closed door, but the wiring in house did not work. I did some investigation on the ring/wiring, and couldn't find any AC or DC interference on those lines. only some back interference once the Ring registered an open/close even on the switch.

To solve this, I ended up using an Arduino to read the house wiring, and then go ahead and close the connection on the circuit attached to Ring. I used relay on the Ring so on power loss the alarm wouldn't trigger as well as for some optical seperation between the Arduino/Ring and the hundreds of feet of antenna running through my walls.

I am in the process of finalizing the wiring and situating all that crap in my existing box as well as running power to that and distributing power to the Ring keypads. I can explain more if you would like.

Back to your point of adding resistors - that shouldn't make any difference whatsoever, since the input on the IC for the Ring is already in series with a 1k resistor on the board. However, a friend has a simplySafe and had to do just that to get his to register.

0
tomdav
tomdav

Reply 9 months ago

This weekend I hooked up 7 hard wired zones to soldered ring wireless contact sensors. I found it much easier to solder into the reed switch leads (it's pretty hard to mess them up) as opposed to the surgical precision required for the modification mentioned in this video:


If you are averse to soldering you can cut the reed switch and twist or crimp wire into the leads (they are that strong) not that I recommend it but I did experiment with one sensor (for science) and can verify the sensor works fine even if you cut the reed switch.

As far as resistors, I found more were needed for (a) longer loops or (b) multiple sensors in a zone. For example, my upstairs door (longest loop) required 4 x 2k resistors. Each of my 3 downstairs doors only required 2 x 2k resistors. I have one hardwired zone with 3 window sensors that required 3 x 2K resistors. You just have to experiment to see what works. If I could do it over I would buy a kit with an assortment of resistors and use the lowest value resistor that works (as opposed to wiring multiple resistors in series).

Why is it necessary to add resistors? No idea but perhaps adding resistors forces the contact sensor to work harder to feed more juice to monitor the loop? If so, hopefully it doesn't adversely impact battery life.

0
riveraj33
riveraj33

1 year ago

Man am I glad I found this site. I’ve found similar instructions for the abode system and have tried doing the same on the new ring alarm sensors. I’ve been able to get one of my doors soldered to the wireless sensors. The hardwired door sensors is one of those recessed version that push in to close and a cylinder comes out when opened. Anyways, I have not been able to get any of my other sensors to work. I’ve soldered them the exact same way but they won’t work. I solder spare wire to the reed switch and then used an IDC connector to reconnect the newly soldered wire to the old wire going directly to the sensor. Any help would be so GREATLY appreciated!

C5EEA374-BCD4-4091-8A77-1963A708DC4B.jpegB4FC2A63-421D-4D29-9970-7D5648C5C8CF.jpeg
0
ejsofla
ejsofla

Reply 9 months ago

Finally got mine to work, made a quick video of my sensors



Screen Shot 2019-04-26 at 8.49.17 PM.pngScreen Shot 2019-04-26 at 8.49.11 PM.pngScreen Shot 2019-04-26 at 8.49.06 PM.png
0
mbeckman
mbeckman

Reply 1 year ago

I've heard from several people trying the SimpliSafe mod on Ring door sensors who also discovered it doesn't work. Apparenlty, unlike the SimpliSafe magnetic read switch sensor, which is either on or off, the Ring sensor change the resistance but doesn't stop current flow completely. That's likely because they use a solid state sensor rather than a magnetic reed relay, which is a mechanical switch. Some people have tried putting a 1K resistor in series with the Ring switch and that has worked.

0
riveraj33
riveraj33

Reply 1 year ago

Thanks, I’ll try that and see if it works!

0
diythis
diythis

Reply 11 months ago

The Ring sensor is also mechanical Reed switch, you can even hear it click when it engages and disengages.
I did the same thing like in this Instructable - bypassing the reed switch so I could integrate it with an existing 'normally closed' old circuit over a couple of windows. It doesn't work to my surprise. The Ring sensor will not detect any changes in the state of the circuit. When I connect it in open state, the Ring sensor shows it correctly as open, when I connect it in closed state, the Ring sensor shows it correctly as closed. But when I change the state (opening or closing the circuit), the Ring sensor will not detect the change.
Directly on the Reed switch I measure 1 Ohm when it's closed. On my circuit in the house there are like 36 Ohm. I wonder if that plays a role.
Next thing is I will connect directly to the pads on the sensor board as in the video below (thanks Cory5). I'll report back if that makes a difference. EDIT: it did not.
Also see here: https://electronics.stackexchange.com/questions/426579/integrate-residential-hardwired-alarm-zone-with-modern-wireless-sensor

0
diythis
diythis

Reply 10 months ago

Yes, and they even downvoted my question, probably as punishment for me commenting that your answer was useful...

Thanks for letting me know about you new post.

I now used an Arduino to solve the problem with monitoring and an initial test was good. It solves the problem with electrical induction by "pulling up" the entire circuit to 5V when it's closed.

0
lcpr123
lcpr123

Reply 10 months ago

Thanks for the update. Can't wait to see your update so I can try it out.

I was unable to get the capacitor to work, I have no idea how the other people who had success wired it into the circuit.

0
Cory5
Cory5

Reply 1 year ago

Not sure if you got this working, but it looks like you can wire directly to the pads on the top of the circuit board. See this video I found (I'm not the author of the video)
I also found that if you apply 3V to the "V" pad, will register as closed, and removing will register as open.

0
charleseford
charleseford

Reply 1 year ago

Hi. I got mine my Ring door sensor to work. I followed the same instructions as graciously provided by mbeckman in this article. At first it didn't work. I checked with my multi-meter and it looked like the current wasn't being broken when the door opened. So I soldered a resistor on each wire from the reed switch and that fixed it. I'm guessing I could have used just one resister, but these were the only size I had laying around and it took two to get it working. I attached an image.

IMG_7802.JPG
0
joekdz
joekdz

Reply 10 months ago

Got my Ring sensors to work this way as well. Had to add 4.7k ohm resistor to each lead coming out of the Ring sensor. Works on all my wired Zones now.
Thanks charleseford!

0
riveraj33
riveraj33

Reply 1 year ago

So I went and tried this out today. I soldered a resistor to each wire in line to the wireless contact sensor. When it’s all connected i went to open the windo and nothing happened. I cut the black wire (the other is red) and the window registered as open. When I take out the resistor from the black wire and tie them up to test it closes when they touch and registers as open when separated. This is all with the red still attached with a 1k resistor in line. Any ideas what could be the issue? Thanks!

0
riveraj33
riveraj33

Reply 1 year ago

Thanks! Are those 1k resistors? How has it been working for you?

0
charleseford
charleseford

Reply 1 year ago

Probably 4.7 ohm. Bands are yellow, violet, red, gold.

It's been working great. No issues.