The main aim of this project is to build an automated garage door opening system that will eliminate the need for remote controls. Remote controls are easy to misplace and require batteries and remote control systems do not check that the doorway is clear before closing the door (refer to the RACV advertisement with the dog).  With the current remote-control system, a stolen remote control could be used to open the door but under our proposed automated system, this would not be a problem.

Control System

We aim to control the system with a Motorola HC11 micro-controller. The main program will be written in C and depending on the inputs, will instruct the micro-controller whether to open or close the door. The main inputs will be two motion sensors (one will be situated inside the garage, whilst the other will be situated outside the garage), a door sensor and a security device.

Security

We aim to use an encoded signal as the security device. The signal will be transmitted and received over a small range (approximately 10 - 20 meters) from the micro-controller. The signal is transmitted by the base transmitter/receiver and is received by the chip on the car. This chip will then proceed to transmit an encoded acknowledgement signal back to the base transmitter/receiver. This encoded signal will then be processed. If the processed signal is true then the door will be permitted to open.

Power supply

We also plan to power the on-car chip via the auxiliary power of the car. This means that when the key to the ignition is turned to Auxiliary or 'start', then the chip will be able to receive and send encoded signals to allow the door to open. This concept was derived from the fact that because we are using motion sensors, that if motion was detected within or outside the garage, then the door would be constantly opening. For example the door would be always opening because the chip would always be active if powered by a constant voltage source (as car headlights are).

Automatic Door Closure

If for some unforeseen circumstances the user is required to leave the garage in a hurry, late for work etc, the user is not required to wait to close the door due to the automatic closing mechanism. The user will be required to only start the vehicle, wait for the door to open enough and drive off. The sensors will do the rest. This will also eliminate the worry of having left the door unlocked.