Using Raspberry Pi + IR Motion Sensor + Google Cloud Messaging + Android

This is a quick experiment where an IR motion sensor connected to my Pi3, sends data to an Android app, via the GCM.

Here's the Flow

Raspberry Pi (I used Pi 3) with a Raspbian installation
A DIY IR motion sensor (you can find some on Amazon)
An Android device
A GCM API Key
An android app registered with your GCM API
App server with the Registration ID from step 5
Raspberry Pi uses the Registration ID to push notifications to client through the GCM server
GCM Server pushes the notifications to the Android app

Pictures of the Pi and sensor wiring coming soon...but feel free to beat me to it ;)