Then I figured if I'm going to make them light up I might as well have them change color. I decided to have them change color every night.
The important parts for this project are an Arduino and an LED strip. I used the LPD8806 from Adafruit. This strip is awesome. It actually has a separate chip attached to each LED. This allows you to do all kinds of cool lighting effects. You could light up the numbers in rainbow colors. Or you could have the colors swirl in a circle or pulsate. Anything is possible.
If all you want are the numbers to change color you could just buy a basic RGB strip and use the Arduino and PWM to change colors. It all depends on how fancy you want your numbers to look.
For now I've got them changing colors every night. Next, I'm thinking I'll add a random function so every night will be a surprise.
Step 1: Parts List
1. Arduino Uno. Any Arduino should work fine
2. LED strip 1 meter. I got this at Adafruit. The model is LPD8806
4. 5v power supply. Also from Adafruit
3. Sheet of 1/4 inch ABS
4. Sheet of 60% acrylic
5. ABS cement
6. 3M double sided tape
7. Misc wire
8. Sheet of 1/4 inch MDF for back