Pauses your program for the amount of time (in miliseconds) specified as parameter.
ms: the number of milliseconds to pause (there are 1000 milliseconds in a second)
nothing
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
}
configures pin number 13 to work as an output pin. It sets the pin to HIGH, waits for 1000 miliseconds (1 second), sets it back to LOW and waits for 1000 miliseconds.