Garage Door Open Detector

Description:

Detects if a garage door is open and if it is dark outside (meaning the homeowner forgot to close the door). The in house unit will blink a red light rapidly in the case that the garage door is open after dark. It maybe accompanied by an occasional beep for those with sight disablilites (model not yet developed). The light indicator will illuminate a green light to indicate that the door is closed. The light will be a warning, yellow/orange color, indicate if the garage is open while it's still daylight.

User's Manual:

Installation and Setup: For installation, apply power to the system (5 volts), and reset the 8051 chips to start normal operation.

Operation: Make sure you have followed the Installation and Setup. After the setup, no user intervention is required, except for changing the power source (if a battery). There are two units to the system. First unit is the transmitter, this unit detects if the garage door is closed (button depressed) and if it is day/night time. You can adjust the sensitivity of the day/night sensor to how dark it must get to be considered night time. The unit has 3 LEDs, one to indicate power (red), one for day/night distinction (yellow, lit=daytime), and one for garage door detection (green, lit=door closed). The second unit is the receiver unit, it contains a power indicator (red) and a dual color LED. The indicator works as follows: If the door is closed, light will be green. If the door is open and it's daytime, light will be an orange/yellow color. If the door is open and it's nighttime, light will be a blinking red. To test nighttime case, be sure to cover the photosensor completely with whole hand.

Implementation:

The following componets were used for the implementation of the device: 2 - 8051 micro-processors 1 - Photocell 1 - potentiometer 1 - button/sensor 2 - red LEDs 1 - yellow LED 1 - green LED 1 - dual color LED (red/green) 1 - set for wireless transmission (transmitter and receiver) and various resisters and capacitors for operation. The red/yellow/green LEDs, photocell circit, sensor/button, and transmitter are connected to the one 8051. The receiver, red/dual color LEDs are connected to the other 8051. Next code was written to both 8051's, the transmitter as 3 cases, garage door closed, garage door open during day, and garage door open during night. The day and night is determined by the photocell, which decreases in resistance as light is applied to the cell. So when there is sufficent light, there will be a 1/0 sent to the 8051. The photocell and the sensor/button are used the determine the state that the system is in. This is then suppose to transmit a byte to the transmitter, which then transmits wirelessly. The receiver should receive the wireless transmission and send it to the 8051. The 8051 will decode the state of the system on its side and illumniates the LEDs accordingly. Project Note: Due to problems with cheap transmitter and receiver units, the wireless transfer does not occur as planned. So the system is hooked up for direct transmission through a wire.

Source Code For Receive
Source Code For Transmit