Now load the 'Blink' example sketch from Lesson 1. You will notice that both the built-in 'L' LED and the external LED should now blink.
/* Blink Turns on an LED on for one second, then off for one second, repeatedly. This example code is in the public domain. */ // Pin 13 has an LED connected on most Arduino boards. // give it a name: int led = 13; // the setup routine runs once when you press reset: void setup() { // initialize the digital pin as an output. pinMode(led, OUTPUT); } // the loop routine runs over and over again forever: void loop() { digitalWrite(led, HIGH); // turn the LED on (HIGH is the voltage level) delay(1000); // wait for a second digitalWrite(led, LOW); // turn the LED off by making the voltage LOW delay(1000); // wait for a second }
Lets try using a different pin of the Arduino – say D7. Move the red jumper lead from pin D13 to pin D7 and modify the following line near the top of the sketch:
int led = 13;
int led = 7;
In the next lesson, we will be using LEDs again, this time, the Arduino will be controlling the LED.
Simon Monk is author of a number of books relating to Open Source Hardware. The following books written by Simon are available from Adafruit: Programming Arduino, 30 Arduino Projects for the Evil Genius and Programming the Raspberry Pi.