|A.||N/A||9V Switching power supply||Part# TOL-00298 @ Sparkfun.com||1||$5.95||$5.95|
|B.||N/A||Arduino Ethernet Shield||Part# 83-13141 @ MCMElectronics.com||1||$34.99||$34.99|
|C.||R2,R3||1/4W 10K resistor||Part# CF14JT10K0CT @ Digikey.com||2||$.08||$.16|
|D.||R1||1/4W 220 OHM resistor||Part# S220QCT @ Digikey.com||1||$.08||$.08|
|E.||R4||1/4W 1K resistor||Part# CF14JT1K00CT @ Digikey.com||1||$.08||$.08|
|F.||IC1||28 pin IC Socket||Part# 3M5480 @ Digikey.com||1||$.70||$.70|
|G.||IC1||ATMega328 w/Arduino Bootloader||Part# DEV-09217 @ Sparkfun.com||1||$5.50||$5.50|
|H.||U1||5VDC Relay||Part# PB874 @ Digikey||1||$1.61||$1.61|
|I.||D1||General Purpose 1N4004 Diode||Part# 1N4004FSCT @ Digikey.com||1||$.18||$.18|
|J.||Y1||Crystal 16MHz||Part# X1103 @ Digikey.com||1||$.81||$.81|
|K.||C3,C4||22 pF Ceramic Disc Capacitor||Part# 399-4344 @ Digikey.com||2||$.44||$.88|
|L.||C1,C2||10uF Electrolytic Capacitor||Part# P5161 @ Digikey.com||2||$.20||$.40|
|M.||Q1||2N2222A Transistor||Part# 497-3108-5 @ Digikey.com||1||$2.76||$2.76|
|N.||J2||Power Jack 2.1mm x 5.5mm||Part# CP-102A @ Digikey.com||1||$.92||$.92|
|O.||IC2||Voltage Regulator 5V||Part# 497-1443-5 @ Digikey.com||1||$.55||$.55|
|P.||LED1||Basic LED (Red)||Part# COM-00533 @ Sparkfun.com||1||$.35||$.35|
|Q.||X1-X4||Screw Terminals (2 pos.)||Part# ED2580 @ Digikey.com||4||$.42||$1.68|
|R.||J1||Male breakaway headers||Part# PRT-00116 @ Sparkfun.com||1||$1.50||$1.50|
|S.||N/A||Magnet Cube (1/4")||Part# COM-08643 @ Sparkfun.com||1||$1.50||$1.50|
|T.||N/A||Reed Switch||Part# COM-10601 @ Sparkfun.com||1||$1.95||$1.95|
|U.||N/A||PCB||Part# GDC10PCB @ jamienerd.blogspot.com||1||$5||$5|
Total (before tax, S&H, etc.): $67.55
Prices tend to fluctuate a little bit, so don't be surprised if by the time you click those links, the prices aren't the exact same. (They may be a little higher or lower)
Technically, you will need a few extra things (you may already have some on hand), such as:
Wire (to run a couple of wires from your garage door controller to your actual garage door opener)
Brackets and screws (to mount to your garage door for the reed switch and magnet)
Some Cat5/5e/6 network cable
And of course there are a few basic tools you're going to need:
Knife (or wire stripping/cutting tool)
The 2 lists above are only a couple of general lists - what you will really need depends on the way you go about your project - you may need more or less tools/supplies.
You'll also need a way to program your microcontroller - an actual Arduino board would be an easy way.
If you want to save a little money, you could skip the screw terminals (Q). This would mean though that you would have to solder wires onto the PCB instead of having the convenience of having 'removable' wires. You could also technically skip the magnet cube (S), and reed switch (T) which is the 'sensor' that can tell you if your garage door is open or not. If you decide to skip those, the Android app would always show your garage door as 'open'. You should probably only skip this if you have another way of knowing the status of your garage door (camera, etc.).
I know this isn't the cheapest project, but to me, it's worth the awesomeness of being able to open/close your garage door with your Android cell phone/tablet! If you want some tips on how you can save yourself a little money, please check out my FAQ, under the 'Is there anything I can do to bring the total cost of the project down?' question.
On the other hand, if you want to spend a little less time (but a bit more money), I have a few options in my store, including full assembled board, or a full kit, etc.