Picture of Simple Arduino 5x2 LED Matrix
This is my First Arduino project so bear with me. 
This a simple LED Matrix that is run by an Arduino Uno 3.
You will need these parts:

-10 LEDs
-Arduino Board
-Jumper Wires
-And some solid core wire

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Step 1: LED placement

Picture of LED placement
Place the LEDs across the middle of the breadboard one LED row on one side and one LED row on the other.
Place the LEDs so that each pin is in a different row on the breadboard. 

Step 2: Grounding the LEDs

Picture of Grounding the LEDs
Then take small bits of the solid core wire and pin them down one the row in which each cathode is in. Take the other end and put it in one of the power slots. When you are done connecting all of the LEDs cathodes to the power slot connect the the two power slots with one long peice of wire.let yet another piece of wire connect to your Arduino.

Step 3: The positive leads.

Picture of The positive leads.
Instead of just putting a jumper cable into the same row as the LED's anodes, I lead some wire out away from the LEDs on the breadboard so that I could attach the jumper wires to them. Away from the LEDs so that it would look better. This improved my project a lot I think.
mangopeach2 years ago
Thanks man. Was a good tutorial. Had a good time doing it.
quatch2 years ago
You should use some current limiting resistors there. You're lucky in that white LEDs have a high Vf (forward voltage drop) and thus don't need a large resistor to keep the current low.

jackjackboom (author)  quatch2 years ago
dont know why they are showing up blue... Odd. I was using my old iphone 3g for pictures so that explains the low quality.
jackjackboom (author)  quatch2 years ago
I am actually using green ones and I have done some simple led things before without burning out any leds before. Although you are quite right. Just didn't have any layin around..