Day one:

Use the Barduino to blink an LED.

Blinking an LED is the Hello World of electronics, the first program you upload to check that everything is up and running. No better way to start the challenge than making sure everyting is ok! Easy one to start the challnge

You can always got to Arduino/File/Examples/01.Basic/Blink, but if you feel a bit more adventurous here you can check a possible solution:

Possible solution!

Arduino code

// constants won't change. Used here to set a pin number:
const int led = 48;  // the LED of the Barduino is connected to pin 48

// Variables will change:
int ledState = LOW;  // ledState used to set the LED

// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMillis = 0;  // will store last time LED was updated

// constants won't change:
const long interval = 1000;  // interval at which to blink (milliseconds)

void setup() {
  // set the digital pin as output:
  pinMode(led, OUTPUT);
}

void loop() {
  // check to see if it's time to blink the LED; that is, if the difference
  // between the current time and last time you blinked the LED is bigger than
  // the interval at which you want to blink the LED.
  unsigned long currentMillis = millis();

  if (currentMillis - previousMillis >= interval) {
    // save the last time you blinked the LED
    previousMillis = currentMillis;
    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW) {
      ledState = HIGH;
    } else {
      ledState = LOW;
    }
    // set the LED with the ledState of the variable:
    digitalWrite(led, ledState);
  }
}

Hero shot