Unlock your door with Siri:
For our first Arduino project, we hacked together a wifi-enabled door lock with some nifty features. After seeing cool projects like John Grathio’s secret knock and Billy Chasen’s ethernet unlocker, we were inspired to build our own. We combined the two ideas using an Arduino and a WiFly shield, a modified servo motor, and a few other things.
The end product is pretty cool and has these features:
- Unlock / Lock your door with your voice using Siri, an iPhone app, SMS, or a mobile web page (iphone app requires iOS developer account)
- Monitor whether the door is locked or unlocked from far away
- Get SMS messages when someone knocks on your door
- Unlock your door with a secret knock (hard-coded for now)
A demo of the iPhone app and secret knock in action:
The Siri hack works by creating a contact called ‘Door’, which is the phone number that we use to accept SMS messages like ‘open’ or ‘lock. We used Google app engine for a server component since it’s free for small usage like this. We then created an iPhone simple iPhone app to send unlock commands and monitor the door state. Twilio.com enabled us to send and receive SMS messages.
All the code we used is available on github here: https://github.com/cclaan/lockerino
* DISCLAIMER * Remember, we hacked this together for fun! – It’s not intended to protect your belongings or loved ones. The code probably has some bugs, might malfunction, or could easily be hacked by someone!
We intend to write up a more detailed how-to on Instructables.com, so stay tuned for that.
Also, this project is probably for advanced builders since your lock may be different than ours and require some custom solutions for mounting the servo to the lock. You may also have to modify our code a little to get the knock detection thresholds and servo angles correct, since they will be slightly different for everyone. Since it requires a web server, you will have to setup google app engine, which is free, but requires a little technical know how.
The total cost right now for all the parts ends up at around $170.. but if you have some of the common parts lying around it could be a lot less. Plus, we hear that the Arduino folks are introducing a cheaper WiFi shield in the next few months, since the one we use costs $90. Or you could use an Ethernet Pro that only costs $54.95 and saves you about 65 bucks, but requires a long ethernet cable.
Here are the parts we used for the project:
Here’s what you’ll need:
A fritzing sketch of how to wire it up:
Here’s a short video of putting it together, again, expect a more detailed tutorial to come soon.
Here’s how to modify a servo to read the position via its internal potentiometer:
Attaching the brackets to the servo:
Let us know what you think in the comments!