2. Power Supply/Regulator

A power regulator on your bread board allows you to plug a 'wall wart' power supply from your wall to your board, rather than powering it off the AVR Dragon programmer. You need the 'regulator' because your board runs on 5v or less. Most power supplies run between 9 -12v. If you tried to power your board with 9 - 12v without converting to 5v or less - things may light on fire, melt, just stop working and generally smoke will be seen. 

You will need the following: 

One 100 or 150 uf capacitor

One green LED

9 to 12v wall wart (power plug for your wall)

One barrel plug (that matches your wall wart)

LM7805

Black and red breadboard wire

330 Ohm Resistor 

This is all just a matter of wiring it up correctly. There is no code to write, nothing to compile, and later you can add an ON/OFF switch.

This is the LM7805:

Figure 1: Image From: http://www.sparkfun.com/tutorials/57

You can find these at any Radio Shack or on SparkFun.com

This is the wiring digram for the power supply: 

Figure 2: Image From: http://www.sparkfun.com/tutorials/57

This is roughly how it should look on your bread board. Wire this up at the bottom of your board to leave room for other projects:

Figure 3 - from full size drawing on the Interrupts How To

The GND wire attaches to the bottom pin of the barrel jack while the VCC attaches to the back pin. 

On a separate part of your breadboard but close to the power regulator, connect the ground wire of your LED to the resistor and the resistor to the ground rail of you breadboard. Connect the other lead of the LED to the power rail of your breadboard. 

If all goes well the LED will light when your board is plugged to wall power!

Detailed Drawings coming soon.