Ouputs either HIGH or LOW at a specified pin.
pin: the pin number
none
int ledPin = 13; // LED connected to digital pin 13
void setup()
{
pinMode(ledPin, OUTPUT); // sets the digital pin as output
}
void loop()
{
digitalWrite(ledPin, HIGH); // sets the LED on
delay(1000); // waits for a second
digitalWrite(ledPin, LOW); // sets the LED off
delay(1000); // waits for a second
}
Sets pin 13 to HIGH, makes a one-second-long delay, and sets the pin back to LOW.