Some more details:
Cobra: The cobra listens for ethernet messages in a specified format. In my case the message looks like this:
Why the 0 at the end you may ask? The cobra listens for more messages then this one. So the 0 is specifying how many parameters are following after the 0.
If the cobra receives this message, it will pulse an output for about 100ms, that output is driving an opto-coupler which in turn is connected to the garage-door control unit.
Voip: My Voip server is an open source package called FusionPbx (practically it’s FreeSwitch with a web-gui). I added an extension on my server (299), and when someone calls that extension, it will execute a small exe I’ve build that puts the required message (see above) on the network.
Now, when my kids come back from school, all they do is dial 299 with the voip client on their android phone and … garage opens, and they can put their bike into the garage.
I’m extending this also with RFID for the smaller kids (10 and 12 years) because they are still to little for a smart phone in my opinion.