Z-Wave Easy Button

I created this Z-Wave easy button to add a big, easy to use, portable control to my SmartThings home automation network. With an easy button, a door sensor, and some relatively easy hacking, I have a button that lets me control any light(s) in my house.

Materials:

• Staples® Easy Button

• Monoprice® No Logo Door/Window Sensor

Tools:

• Third Hand or Vise
• Electric Drill
• Knife
• Needle Nose Pliers
• Small Philips Screwdriver
• Soldering Iron

The first step is to disassemble the Door/Window Sensor.

On one end, you'll find a small philips screw. Remove the screw and then pop off the back of the sensor.

Inside of the sensor, you'll see that the circuit board is held in place with another small philips screw. Remove that screw and you can easily pull the circuit board out of its enclosure. The circuit board is the gold here, recycle the rest.

The Easy Button is only slightly harder to take apart.

First, press the button one last time.

Then, flip the Easy Button over and remove the batteries. You will see four little rubber feet. Yup, this thing has full LRF support. Use your knife to pry them off. It's easy and there's only a little adhesive holding them on. If you keep the adhesive clean, or replace it, you can reuse the feet when you are done.

Under each of the rubber feet, you will find a philips screw. Remove the screws and your button separates easily. Make sure to save the screws.

We need to get this little baby further disassembled. We're going for individual bits here.

You can see that the circuit board that controls the Easy Button is held in place with two screws. Removing the screws allows you to lift the circuit board up to expose the clicker.

The clicker lifts right out exposing two more screws. Remove those two screws and the two others holding down the plastic mount. Then you can lift out the mount and you'll see the speaker and two weights laying in place on the button's base. You can lift out the speaker from its home.

Don't forget to save the screws!

The circuit board has a nifty switch that lines up perfectly with the button when it is screwed in place. Reusing it saves us a lot of fiddling around to create one of our own. There's also four wires connected to it, which are exactly the number of wires we'll be needing for this project. So if you can save them, that's like 5¢ saved!

You can track the wires to where they connect to the circuit board. You can see the 2 pairs of solder joints on the opposite side as indicated by my handy screw driver/pointing device. To unsolder these joints, simply heat them up with your soldering iron while pulling on the wires from the behind side. If you do it quickly enough, you won't melt the insulation on the wires.

Once you have separated the speaker from the circuit board, you'll want to reclaim the wires attached to it. Simply heat up the solder joints on the speaker and pull the wires away. These will work well for attaching the button later.

The speaker is yours to do with as you please.

In its original incarnation, the door/window sensor would have held a relatively expensive 3 volt battery. The Easy Button comes with a mount for two 1.5v AAA batteries. Two time one and a half makes 3 volts. It's like they wanted these things to go together.

The door/window sensor connects directly to two spring terminals for the expensive battery. We don't want these terminals, but we do want to use the holes they are connected to. That means more unsoldering.

The easiest way to remove these terminals is to hold the circuit board in a vise or third hand, with the terminals away from you. Then heat up the solder joint and, with a pair of needle nose pliers, bend the terminal away from the circuit board. You can see the process illustrated in the pictures above.

The door/window sensor is designed so that you can optionally wire it up to a second switch in addition to the built in magnetic reed switch. There is a handy screw terminal on one end so you can easily connect the wires for your switch. Unfortunately, though we want to connect wires here, the screw terminal takes up too much space. More unsoldering!

You can sort of make out the screw terminal, as indicated by my handy pointing device. On the reverse side, you can see two solder joints carefully guarded by the sensor's antenna. We want to unsolder the terminal without disturbing the antenna.

It's a little difficult to see in the picture, but I removed the terminal by heating up both solder joints simultaneously and pulling the terminal away from the opposite side. A bit of a rocking/pulling motion may help.

Next to the former home of the screw terminals, there is a male header. This header is probably used for programming the door sensor at the factory, and it could be great if we could alter the programming, but it's not documented and we don't need to do all that to get a working button.

This header sticks up too far to fit in the easy button, but I don't want to go through the effort of removing it, so I simply bent the pins over. Grab ahold with your needle nose pliers and bend away.

Earlier, we removed the screw terminals where we would have connected wires to the sensor. So now we need to connect the wires the hard way.

The wires we want are the two red wires we scavenged from the speaker. Since the wires were already tinned (coated in solder), it is fairly easy to simply heat up the solder joints and poke one end of each wire into the respective holes from the screw terminal. You can use fresh solder to help the process along and ensure a solid connection. The way I connected the wires ran them under the antenna. This seems to work well.

On the door sensor, there is an LED indicator. This indicator is useful for the process of pairing the Easy Button to your Z-Wave network, so I kept it around. In order to be able to see it, and in order to have room for the circuit board inside the button, we need to make a hole for the LED to poke through. Fortunately the Easy Button came with a whole bunch of holes we can use as a guide.

I chose the hole closest to the battery compartment and enlarged it. The LED is a 3mm LED, so you can use either a 3mm drill bit, or, if you prefer the proper Freedom Units, a 1/8" drill bit will be great. Just chuck the bit and drill out the hole.

Now it's time to hook up the sensor circuit to the battery compartment. The batteries come with two handy wires, one white and one black. In my case, the black wire was the negative terminal and the white wire was the positive terminal of the batteries, which I would consider backwards, but no matter… there's a little plus and minus etched into the battery compartment so you can double check.

We removed the two battery terminals from the circuit board, so we now have a place to connect these wires. It's not a standard hole, so I found it easier to solder the wires directly to the surface of the board.

On the circuit board, the negative battery terminal is the side closest to the male header we bent over. So I soldered the black wire to this point. The positive terminal is closest to the reed switch, so that's where I connected the white wire.

As I said before, the circuit board from the Easy Button is nice in that it mounts a switch in a manner that securely lines up with the button when it's pressed. The only problem with this circuit board is that it only has solder holes connecting to one side of the switch. That means we will have to come up with another way to solder connect to the switch.

Fortunately, the circuit does expose the trace from the switch to the microchip that utters Staples' slogan whenever pressed. We can use this trace to connect up to the switch.

In the second picture for this step, you can see that I have highlighted the trace in blue. What you will want to do is take a sharp knife or razor blade and scrape the green solder mask off this trace in this area. Don't scrape too hard, you need to leave the shiny copper behind.

Since the trace is connected to the microchip on this board, the microchip will interfere with the sensor board reading the switch when it is pressed. To prevent this interference, you need to cut the trace before it gets to the microchip. In the second picture above, I highlighted in red where you'll want to cut. Again, with a sharp knife, score across this point in the circuit board. This time you want to go all the way through the copper so there is no possibility of connection. Since you are cutting through (very thin) metal and into fiberglass, this can dull your knife, so I suggest using someone else's.

Now you can solder the red wires from the sensor board to the switch board. One wire will need to connect to the trace you scraped clean and the other will connect to a more useful solder hole.

In the first picture above, I highlighted two solder holes you might want to connect to. I used the one highlighted red, towards the right side of the board. Afterwards, I decided that the one highlighted in blue, below the switch in the picture, would probably work better. It's up to you.

The other red wire needs to solder to the trace you scraped clean. To do this, you'll want to heat up the trace and apply a very little bit of solder to it. This is tinning the trace so the wire will make a better connection. Apply your soldering iron to the trace for a second or two and then, keeping the soldering iron in place, lightly touch some solder to the trace. The solder should wick across, but you can help it along a bit with your soldering iron if necessary. Just don't let any electrical engineers see you do that. Then you can solder the wire to the tinned trace.

Now's a good time to look things over and make sure that your solder joints are nice, the wires are secure, and that there're no solder bridges between terminals, etc.

Replace the batteries in the battery compartment. Now you can go into the SmartThings app and tell it to Connect New Device. It'll search and eventually show a new Z-Wave Sensor. Give it a name, like "Easy Button". Unfortunately this sensor is just a generic Z-Wave sensor, so you'll need to go into the SmartThings IDE and add a new device type. I have a device type on GitHub that uses a Door/Window Sensor as a button. You'll need to edit your device to use this device type. How to go about that is better left to the good folks at community.smartthings.com.

Once the device type is set up, you'll be able to check it's activity by pressing the button on the switch board while holding down the black switch on the sensor board. The switch is adjacent to the header you bent over on the sensor board.

To actually get the button to do something useful, you'll want to add a SmartApp from my GitHub repository that toggles lights when it detects a button press. Again, setting up a SmartApp is a bit much for this instruct able, but you can find out how to do that on at smartthings.com.

Now it's time to put our newly improved Easy Button back together.

First, you'll want to place the sensor board. Poke the LED out through the hole you enlarged.

Next, place the mounting board in place and screw it down with four of the screws you remembered to save. Then you can put the clicker in its home and screw the switch board on top with two screws.

The button for the Easy Button should now line up, and the trim ring will finish it off.

Turn the button over and you can replace the last four screws. Then its a simple matter of reimplementing the four-point LRF support.

Now that everything's hooked up and screwed together, you'll want to test the thing one last time.

That was _______.