Use an Android phone or tablet as a door minder or motion detector. The application uses the camera on your device to detect movement and if motion detected give a sound notification. Door minder can be used in a shop or at home to indicate that a person has entered the monitored zone. Get a sound notification if your pets go to where they are not allowed.
How to use:
The phone needs to be placed in a stationary position with the camera pointing to the monitored area. Use a external Bluetooth speaker to extend the range and location of the sound notification. Because the phone and camera needs to be on all the time it is best to have the device on charge.