This is a basic project for Arduino – an expansion of the Blink sketch included with the Arduino software.  You don’t need many parts for this:

  • 1 – 5mm red LED
  • 1 – 5mm green LED
  • 2 – 220R resistors
  • 1 – jumper wire
  • 1 – breadboard (I used a 170-point mini board for this)

The flat (-) sides of the LEDs will be connected to ground.  The rounded (+) sides will be connected to 220R resistors which are in turn connected to pins 12 (green) and 13 (red) on your Arduino Uno.

 

Blink_2_bb

 

You can power this either via USB (convenient if you’re making changes to code) or via battery.  I use a 9V battery connected to a barrel plug.

 

For the Fritzing file and the Arduino code, please visit this project’s page on fritzing.org