Timer
by BARRAGAN <http://barraganstudio.com>

Demonstrates how to create a timer to turn ON an LED after certain time has passed since a switch is pressed

Created April 30 2007
 

    
// Timer 
// by BARRAGAN <http://barraganstudio.com> 

int ledPin = 48; // Wiring hardware diagnostic LED on pin 48 
int switchPin = 1; // Switch connected to the Wiring I/O board pin 1 
long previousTime = 0; 
 
void setup() 
{ 
  pinMode(ledPin, OUTPUT);   // sets the digital pin as output 
  pinMode(switchPin, INPUT); // sets the digital pin as input 
} 
 
void loop() 
{ 
  if(digitalRead(switchPin) == HIGH) {  // if the switch is pressed 
    previousTime = millis();		// save the actual time 
  } 
  if((millis() - previousTime) >= 7000 ) {  // if 7 seconds have passed since started counting 
    previousTime = 0;			    // reset saved time 
    digitalWrite(ledPin, HIGH);		    // turn ON the LED 
  } 
}