Ever wanted a color-changing LED array above your bed or in your living room ? Want to make your own Christmas lights ? You want to control exactly how your LEDs are going to behave ? Have an automatic turn ON/OFF, different colors on every different day etc...

Also, this project is pretty easy, fast en cheap to do. You need about 10$ for the electronics (if you don't already have any) then as many LEDs you want !

What do you need ?

- A RGB LED Strip, you can find them for about 2$/meter or even cheaper on some websites. Look at my pics to see how it looks like.

- An Arduino, any kind is good, you can also use Nano or Mega, not only Uno (1$ to 10$)

- 3 Transistors, I used P2N2222AG here because I didn't have anything else

- a breadboard if you don't like soldering

- a few wires

- 3 resistors (I used 1k for mine, check your datasheet)

- a 12V power supply (mine is 2A, costs about 2-5$)

Let's get started

Step 1: Building the Circuit

First, check how many Amps your LEDs need. If you know their specifics, you can calculate it:

- I they are 12V and 24W leds, you'll need 24/12 = 2A !

- If you don't know these specs, use an Ampmeter, mine use 600mA each, choose your transistors accordingly

A transistor is a 3 pin little guy, the middle pin is usually where you are going to "give the order" with Arduino (put the resistor on there). The collector is where you are going to put your GND coming from your power supply, you'll plug your LEDs on the emitter.

Now do this for all three of the colors (RGB).

The code is fairly easy, here is the link: http://pastebin.com/Pa7wcU5b

Modify it accordingly to your preferences.

Plug everything in, the +12V directly on the LEDs, here you go !

Watch the video if you can't manage to plug everything in right.

Any questions ?