My roomate started an arduino project for this and we used the sonic sensor perpendicular to the ground to be able to tell how much the door was opened too (by

My roomate started an arduino project for this and we used the sonic sensor perpendicular to the ground to be able to tell how much the door was opened too (by measuring how close the top side of the door was to the sensor as it moved closer to the door opener). To "talk" to the door we ended up buying some sort of universal remote controller that we tore apart to change the button you press for a relay that the arduino was able to use. A raspberry in front of the arduino ran a webpage and more smarts. We tried to make mac address detection on the wifi network to realize our phones connected home after work, but ended up not using that as it felt risky.