My project uses Arduino Mega 2560, distance collision avoidance sensor, echo distance sensor, relay switches, RTC clock, and wired connection to the garage door opener. I can monitor the status of the garage door, view video camera, open/close the door, auto close the door after specified timer, etc. It serves as a web server. It has been stable for about two years. Arduino sketches enhanced to detect the changes in IP address, check and adjust time, using external PHP server which is not available to Arduino, etc.

The 13 files are uploaded.

Step 1: Parts Needed (around $60)

8 GB micro sd card for storing web server files. 4GB will do. There are not many files.

Ultrasonic Module HC-SR04 Distance Measuring Ranging Transducer Sensor

$1.93

Ethernet Shield Module W5100 Micro SD Card Slot For Arduino UNO MEGA

$7.35

5V 4 Channel Relay Module For Arduino PIC ARM DSP AVR MSP430 Blue

$4.00

DS3231 AT24C32 IIC High Precision Real Time Clock Module For Arduino

$1.84

Mega2560 R3 ATmega2560-16AU Control Board With USB Cable For Arduino

$9.49

Infrared Obstacle Avoidance Sensor For Arduino Smart Car Robot

$1.96

Test Develop DIY 830 Point Solderless PCB Bread Board For MB-102 MB102 $3.55, power supply (5V) and 120Pcs 20cm Color Breadboard Jumper Cable Wire Combination For Arduino $4.35

optional: 4 Channel Wireless RF Remote Control Transmitter Receiver Module

I use it as a remote control. The RF signals are sent to the Mega 2560 to trigger relay to open/close the garage door. $3.45

I bought mine from http://www.banggood.com/ but you should shop around. Take longer to wait but it's cheaper.

Step 2: Wiring All Together

To be done later.

Step 3: Arduino Mega2560 Sketches Outline

Here is the main menu. Quite a few you don't need. I crossed a few of them. Only four left.

1. Current Garage Door Status:

Using the two sensors, ultrasonic distance measuring and Infrared Obstacle Avoidance Sensor to determine the distance of the top panel of the garage door. If it is less than XX inches then the garage door is open, else the door must be closed.

2. Open or close double garage door 3

I have two garage doors to control. This is the main one. Click to open or close. It requires security pass code to enable the button. You will need an external web server that can execute php codes.

3. Disable auto close timer (will not automatically close)

Used for opening garage door for extending period of time. It will not close when timer (7 minutes) is up.

4. Rest auto close timer to default 7 minutes

When the garage door is open for 7 minutes it will close without warning.