Build a Simple Door Detector With IFTTT Alerts Using Arduino
One of the most important parts of any home security system is a door detector that tells you when a door opens. On Adafruit they show you how to create your own, which is connected to the IFTTT, so you can be notified by any convenient manner, when the door opens.
The system uses a cheap Arduino board, several sensors and a magnetic contact switch. It then connects to Adafruit IO and connects to IFTTT, so you can set up alerts in any way you like. If you’re building your own home security system, this is a pretty sane place to start.
Using IFTTT with Adafruit IO to Build an IoT Door Detector | Adafrut