Over the last few weeks I have been searching the interwebs for ways to extend the functionality of my smartwatch. Tasker is a great starting point and is available for most of the current watches. My searches led me to this guide for an Android phone for opening a garage door and I figured I could accomplish the same with Tasker and my smartwatch.
From the start the of this project the goal was to keep costs down and have it available readily available across platforms. I believe I have ticked these boxes with the parts list coming in under $40AUS, functionality across most Android phones and already two smartwatches. Enough chit-chat — lets get into the fun stuff and build a Bluetooth switch!
I live in Australia and we are not fortunate enough to Amazon available for small purchases like Bluetooth headsets and we also don’t have Radio Shack. Not to worry — I headed off to my local Jaycar (Radio Shack equivalent) to pick up the small electronic parts.
Here is the list of what I purchased:
I bought spares and it still only cost $5AUS.
Next stop was a cheap electronics store for a bargain basement headset. I couldn’t test any so I just grabbed the cheapest set they had and these were $27AUS.
If you have an old set laying around you just saved yourself $30!
Once back home the first thing you need to do is charge up the headset and pair it with your phone. Once paired, put the headset on and connect/disconnect with the device. The headset should make a noise — if you are lucky it will beep on connection. This is very important and will determine how Tasker operates.
Now we want to get the unit ready to connect our transistor to the active (red) cable of the speaker. On my unit I simply pulled the rubber ring off, leverld the speaker up and cut the top of the wires with some sharp scissors.
Then, remove the rest of the speaker assembly so we can work on the wire. I squashed it with some pliers and cut down one side.
While we are here, unwind the cables and cut off the black. Also scrape some of the insulation off the red cable end.
Now with the flat part of the transistor facing you, the right leg needs to be jammed into the charging port with the USB connector inserted. It’s a good idea to sand/grind the connector down a little so it all fits in easier. I found the transistor legs to be quite fragile so I used a straightened staple instead. The middle leg then needs to attach to the 30ohm resistor and this in turn connects to the red speaker cable. The resistor is tricking the unit into thinking the speaker is still there.
The red cable that was bought earlier connects to the remaining leg of the transistor. The black cable wraps together the staple and the transistor leg.
You may notice no solder in the above pic. I actually used instant glue (Loctite 406) to hold everything in place and perform initial testing. Be warned though it does not conduct electricity and you will need to solder. I am a novice with the soldering iron and still managed to do an okay job at it. The glue melts away and you are left with a nice solid contact.
Congrats you now have a Bluetooth switch!
I live in the wet tropics and didn’t really want this device out in the humidity or on display next to my door opener. However, it is possible to simply connect the red and black cables to the back of the unit at the appropriate terminals. Garage doors vary however, there should be a remote/door switch input just waiting for your Buetooth switch. This would be a nice quick installation method.
I decided to use my existing wireless remote and this allows me to leave my Bluetooth inside and out of the weather or even in my car.
Opening the cover off my remote showed me this:
A nice big switch to connect to, I simply took some wire and shorted two pins on the switch at a time until the light turned on. Once you have your two pins solder the red and black cables to them. I found it easiest to flip it over, glue the cable in place and dab the solder on top.
With your remote in range of the door and your phone in range of the Bluetooth, it's time to test. Open Bluetooth settings, connect to the headset and then disconnect. Your door should now open when your headset would have beeped. If nothing happens, go back and check all your soldering and confirm the unit is on.
For this you will need the Tasker app and the secure settings plugin.
After lots of testing I have decided on the following Task:
The wait is needed to allow the device to connect. If your device beeps on connection there will be no delay. If it beeps on disconnect you will have the 3sec delay. The wait will also vary between devices so trial yours to get the fastest time. Too fast and you will get BT connection errors from secure settings.
Here comes the fun part! Map the task to the Tasker app on your watch, head outside and gloat in your awesomeness in front of the neighbors!
Check out the video up top for a look at the Pebble and Sony Smartwatch 2 in action.
Notes: My headset is only visible to paired devices or when it is in pairing mode. This will keep security just as high as before the mod. Of course do all this at your own risk and try not to break anything — it's not anyone's fault but your own if you screw something up. If you have any questions feel free to ask them in the comments!