Arduino Traffic Light for Beginners

This is my first instructables, so it'll be quite simple. I bought an Arduino, and I decided to make it into a traffic light, but I only had Red and Green LEDs, no yellow or blue. So this is what I made: A traffic Light that flashes 3 times before changing color. 
Before you start, you should know that I'm only 13, so this will be a fun experiment for people who are learning about engineering using the Arduino. It's extremely helpful. I'll also be explaining some basicis about the Arduino during the steps.
So here's what you'll need:
- An Arduino (I'm using the Arduino UNO, but newer kinds will work as well)
- The Arduino software (here is a link to download it: http://www.arduino.cc/en/Main/Software )
- 2 Resistors (mine are 220 ohms ±5%) (That means the marks on it are Red, Red, Brown, Gold)
- 2 wires or any piece of metal to connect the LEDs to the Arduino
- 1 Red LED
- 1 Green LED
- 1 Breadboard (Or the arduino prototype shield, with which you won't even need the wires)
You can get all of this in the "Getting Started with Arduino Kit", which you can get at http://www.makershed.com  for $75.00

Step 1 Board Setup

1. OK, so the first step to your Traffic Light is to set up the Arduino Board
To get started, put the LEDs in the breadboard. If you're using the breadboard that comes with the Kit, you can see that it'll have 10 colums (A-J) with 30 numbered rows. The rows are connected on the same number from A to E and from F to G on any 2 different numbered rows. So you have to put the LEDs in separate numbered rows. I put them in these positions:
Long Green: E15
Short Green: E16
Long Red: E8
Short Red: E9
Now you gotta connect the long legs to the DIGITAL pins and the short legs to ground, using a resistor. There are 2 very convenient GND (ground) pins on the section labeled POWER on the Arduino. I put resistors from A16 to one of them and A9 to the other. Then, using a piece of wire, I connected B8 to DIGITAL pin 9 and B15 to DIGITAL pin 10. There! You're done! Simple as that.

Comments

[billbillt]

I like this one...Good at explaning what is going to happen...

[figital]

I'm working on this now using some relays and a 12 volt light I got here: http://lanecontrols.com/traffic-lights. Hopefully to plug into an ethernet-shield for internet access.

[Chrishugh]

Great job. Very helpful.