GSM Enabled Security Door

The security door at the front of [Oliver’s] building uses an intercom system to let in guests remotely. Each unit has an intercom handset with a button that unlocks the door. [Oliver] wanted a way to enter without carrying any extra items so he built a system to unlock the door with his cell phone.

He patched into the intercom and attached a GSM module. The module runs python so he wrote a script that will monitor the entryway buzzer, then wait for an approved cell phone connection to unlock it. He went through a couple of different iterations for the final project. The first attempt used XBee modules to communicate between the intercom handset and the GSM module. For the final version, he snaked cable through his wall using rare-earth magnets (creative!) in order to forgo the use of a battery in the handset.

Who doesn’t carry a cell phone with them?  Because of this, the use of GSM modules in automation is a trend we think will continue to gain popularity.

14 thoughts on “GSM Enabled Security Door

  1. If you say so Neckbeard!

    Ironically in a v.early version of this project I had trouble getting the XBee and GM862 module to communicate serially and resorted to an Arduino with XBee shield to pass information between the XBee and GM862 module. When I eventually managed to overcome the difficulty getting the serial communication working I no longer needed the Arduino and so, as you have noted, it is absent.

  2. great project and well documented. i see how this lets you in your building but how do you open your apartment if you have no keys? do you have a keyless project in the works for that? maybe another xbee and a servo that responds to the same cell call.

    1. Thanks for your kind words cath0de. You’re absolutely right of course, I still need a way to get into my apartment (not just the building) without key. I do have some thoughts along the lines you suggest servo (or possibly an electric strike) triggered by same GSM module. I’m busy with other projects at the moment but I do hope to get round to this. As it happens the one time I was locked out, I had left my apartment door open!

  3. Yeah, this is a really nice project, kudos to you, Oliver.

    Yet, spending $159 on a component to open my door would be too much for me :) I would probably just pick a $15 used phone and connect it to a cheap µC via serial cable, using AT commands.

  4. Even if you spoofed his caller ID exactly, you still need to know his password, so no, you are not getting in.

    That, and you would also need to know what number to send that password text message to.

  5. I like the units that have the door opening relay in the box next to the door. Just need to remove that box, connect two wires and you’re in!
    I think I’m going to hook up mine too.

  6. @IceBrain Dude then you wll have to spend some serious time doing the cell search cos the only ones ready for the task were the old nokias and ericssons… Easiest call, a module. But yeah… quite expensive, even the Telit is like 99$.

    Now I propose: What about using a Bluetooth modem and leave a cell phone or pc online in the house? The bluesmirf are way cheaper than a GSM module, and everybody usually leave the computer online. It would need some more programming but… I think is a nice shot.

    By the way Oliver great work!

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