Making your own versus buying something already made… the conundrum.
Our apartment here in New York has one of those newfangled RFID entry systems. We don't have a door man, so you wave your RFID tag in front of a reader at the door and it automagically unlocks. It's all fine and good unless you have someone visit. You can make copies of your apartment key, but it's pretty difficult to clone RFID tags.
The problem: unless your visitor wants to spend their entire time with you or you want to give your RFID tag up… someone will get locked out.
That got me thinking, how else could we let people in to the building?
The Possible Solutions
clone the RFID tag
intercept the in-apartment unlock button to remotely unlock
adopt a dog, train it to open the apartment door, walk downstairs and open the building door
Cloning the RFID tag seems to require an effort and hardware I don't have beyond what I want to get involved with and a dog doesn't seem like the right thing to adopt right before grad school, besides, I have Stanley!
Doing a Google search It looks like other people have built similar systems. Essentially, you send a text message, magic happens in the series of tubes and the door unlocks. I built a working prototype today.
My system would use an Xbee at the button [it's far from the internet box] to activate a transistor which would activate a relay, effectively 'pressing' the button. This part works just fine. (a few technicalities, The complexity isn't as much the hardware as the software that ties it all together.
You need a service to receive text messages, an intermediary web server to translate what the messages mean and send the command to the arduino [it looks like you might be able to do this with within Twilio], the Arduino plugged into ethernet to get the command w/ an xBee & the xBee at the button. All in all, while I think I could eventually make this work, it will take a really long time.
Enter, Lockitron. It's a hardware + service that came up during some deep Google searching.
It's a hardware & software solution that does basically what I want to do. They even have a hardware device that has relays, just like what I was building. Sweet. And after chatting with the folks who created Lockitron it looks like I might be able to connect some contraptions to the other relays. Bubble Machine?
In the end, it seems like this will be the way to go for now. Perhaps after I learn more about the code end of software/hardware services at school, I can interface this with a future creation. [looks like Lockitron uses Twillo after all!]
