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.

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.

Comments

author
ThomasP157 made it!(author)2016-09-16

I did the first sensor exactly as described, but realized that I could route the wires through the back of the case as shown and better cover the holes left in my walls from the previous sensor. In my case, the old sensor had a switch wired behind the molding that ended in the door frame, and a magnet embedded in the door. Soldering the existing sensor into my new SimpliSafe transmitter as described worked like a charm!

IMG_7351.JPGIMG_7352.JPGIMG_7353.JPGIMG_7354.JPGIMG_7355.JPGIMG_7356.JPGIMG_7357.JPGIMG_7358.JPG
author
SimmermanF made it!(author)2017-01-19

Super helpful as I replaced some old GE Interlogix sensors - thanks!

author
mbeckman made it!(author)2016-09-16

Sweet, Thomas! The versions of the switch I have don't feature that opening to the back. It's almost like SimpliSafe is preparing for a wired version of the switch! Your pics are fantastically clear and detailed. Thanks!

author
hele808 made it!(author)2017-01-04

Great instructions. Wanted to add that I was able to do this with sensors bought this week without removing the circuit board and battery connectors. I used a soldering iron to poke a whole through the plastic sensor and ran the wires through there and to the side of the battery. I cut the wires staggered so there was no excess and looped and soldered them. So far so good on 4 wireless units monitoring 13 windows and a pair of French Doors. I used wireless sensors on the three main doors and 4 critical windows however I might go back and swap these to the pre-wired and use the extra sensors to monitor the upstairs. I wish Simplisafe would either build this in or offer a multi sensor with a 4 zone block on it.

Wires.jpgHole.jpgPreWire.jpg
author
Barryjohnson5482 made it!(author)2016-10-19

I have ordered all these parts. I am making a perimeter alarm at my storage lot. Which alarm out put would I connect the wires to so the entry sensor will trigger? Worried about the voltage coming off the receiver into the sensor. Thanks

Screenshot_20161019-162943.png
author
mcdermottmb made it!(author)2016-07-05

OK. So I have the SS2 and I took an unused entry sensor, I snipped the leads to the reed switch and soldered on two wire leads. Now the sensor doesn't work at all. If I touch the two leads together then hold them apart, nothing happens. If I ground the lead on the fat end of the board to the metal bar over where the reed switch was, it registers with the base station as an entry sensor. Has SS changed something in their sensors to defeat this hack?

author
eakur made it!(author)2016-08-18

I don't why felt need to cut the legs. That might have something to do with it. Not sure. But I wonder if you accidentally cut Antenna, instead of reed switch.

I just installed mine with wires on reed switch and works fine.

author
mrubiotx made it!(author)2016-07-06

Can someone please confirm if this still works with the latest (July 2016) version of the SS entry sensor? (That is basically the factor that will determine of I go with SS or move to something else) .. Thank you

author
mrubiotx made it!(author)2016-07-06

Can someone please confirm if this still works with the latest (July 2016) version of the SS entry sensor? (That is basically the factor that will determine of I go with SS or move to something else) .. Thank you

author
eakur made it!(author)2016-08-14

it works

I purchased it from amazon and tried it last night.

Worked just fine with my wired sensors

author
JoeT94 made it!(author)2016-07-16

Let me know if you figure out how to add a relay to the standard SimpliSafe SIren so that I can set off something that I can actaully hear! Thanks!

author
MarcGoldstone made it!(author)2016-02-14

What about using an existing hard wired siren? Does the base station have an output that could drive a relay? How?

I have both FireX wired smoke alarms (independent of the alarm panel) and a fire/smoke detector hard wired into my existing alarm. Can one or both be used with the SimpliSafe? If using a door/window module interfaced with the hard wired detectors can the system be programmed to report an alarm as fire vs. break in?

author
edisonman1952 made it!(author)2015-12-22

Hi, Was wondering if you take this switch that you hardwired and connect to the siren, would that set off the simplysafe. I have a wired Brinks system fully operational this way you can use the wired system with the wireless. Do you think that might work ?

author
mbeckman made it!(author)2016-01-24

I don't see how txt would work. SimpliSafe doesn't send a signal out to the awitch, it only receives switch state.

author
markmiles made it!(author)2016-01-24

Nice job on this. Has anyone looked at how to trigger an existing hard wired siren to the SimpliSafe system?

author
Dan+in+sunny+FL made it!(author)2015-08-22

Thank you for figuring this hack out. Like many others I have a hard-wired house and I'd like to use some of the original senors. I guess my next step will be to figure out the jumble of wires in the pictures and see what happens.

I guess I'll unplug the power & common and and test the lines to see if the contacts complete the circuit. This hack should allow me to use them, right?

Any advice would be appreciated.

Thanks

Old Wires.jpg
author
Dan+in+sunny+FL made it!(author)2015-08-28

So, my layout as you can see near the bottom of the picture above:

Com

Zone 5

Zone 4

Zone 3

Zone 2

Com

Zone 1

I have continuity between Zone 1 and Com when the magnetic switches are closed and a break when I open a switch. My SimpliSafe sensor is rewired to work and touching the leads sends a signal to the base (in test mode) that the sensor is open. But, no matter which way I wire it to the Zone 1 and Com wires I cannot get the magnetic switch to trigger the SimpliSafe sensor.

Very frustrating. Should I plug the old alarm into the wall outlet? There's a resistor inline between the Com and the Com wires (there's two wires for the Com & Zone 1 to the mag switch). I've tried going around it and that doesn't help either.

Can someone give me some idea of what to try next?

Thanks

author
IcantBelieveItsNotMayonaise made it!(author)2015-09-07

Dan, I don't know if anyone responded but I'm doing the same thing you are w/ my old alarm. Don't plug in the old alarm, in fact, disconnect the battery back up unless you are using it for some reason.

Making the old wired window/door sensors work: The SS sensor uses the magnet to hold the reed switch closed. This is call NORMALLY OPEN (NO). When the magnet is removed, the reed switch rests/ opens (NO) and sets off the alarm. I cut out the reed switch and soldered the leads from the wired window sensor and it works the same way. Make sure you check your old sensors. Some are NO some are NC (normally closed). It sounds like yours should work as-is, but I would disconnect them from the panel and just use the two sensor leads. Also, because it operates NO, if you are using one SS sensor with multiple wired Sensors, they have to be wired in series so that any one breaks the circuit. If they are wired in parallel it won't work. Photo's to follow as soon as I have time.

author
davidandbecci made it!(author)2015-06-23

Just what I was looking for. Thanks for sharing!

You say SimplySafe uses proprietary Zwave protocol and provisioning. Does that mean it won't connect to the Wink Hub or other smart hubs that support Zwave?

author
mbeckman made it!(author)2015-06-23

Right. It's not compatible with open systems.

author
mbeckman made it!(author)2015-06-19

Eric31,

I never mentioned that it can be used with existing _smoke_alarms. This is a door switch for an intrusion detection alarm system. In any case, the module only works with the SImpliSafe system, as it uses their proprietary Zwave protocol and provisioning.

author
erics31 made it!(author)2015-06-19

You mention this can be used to with existing smoke alarms. How would you connect this to the exiting smoke alarm? My house has interconnected smoke alarms so it would be nice if one went off it would trigger the base station.

author
cbalentine1969 made it!(author)2015-06-10

I made this! Does anyone know what setting to set the sensor on in my system?

author
mbeckman made it!(author)2015-06-13

It remains a door switch as far as the alarm system is concerned.

author
vageesh79 made it!(author)2015-06-13

Great idea i was looking for something like this to add wireless doorbell to my zwave network but the problem now i am facing with sensor is that without magnet the reed switch is always open and when i connect wires connected to reed switch then only it closes. Can i reverse this without changing the reed switch in sensor config.

author
mbeckman made it!(author)2015-06-13

That's the behavior you would want with a doorbell: pressing the button closes the circuit. With the magnet not attached, the magnetic reed switch is open and essentially out of the circuit. You're simply wiring your doorbell button in parallel with the reed switch.

author
rodgersfam1980 made it!(author)2015-05-27

This was quite educational...THANKS! Gives me some great ideas.

Now, a related question: Has anyone disassembled a SimpliSafe MOTION sensor?

The Motion Sensor guts don't seem to snap out like the entry sensors do. Rather, they have some long, thin, hollow posts that seem to be permanently mounted.

I'd like to get access to the interior guts, in order to solder an antenna wire lead to an external antenna. The goal is to extend the range to allow an out-building to have a motion sensor.

Any comments or pointers in the right direction would be greatly appreciated!

Jimbo

author
mbeckman made it!(author)2015-01-03

I hope SImpliSafe takes the hint and offers a model with screw terminals. It's a no-brainier and I can't imagine why they've gone years without this capability.

author
tomatoskins made it!(author)2015-01-02

I used to work for a security company and I've done this very thing before. Great job!

author
seamster made it!(author)2015-01-02

Great work! Thank you for sharing this guide.

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