/* Arduino Starter Kit example Project 8 - Digital Hourglass This sketch is written to accompany Project 8 in the Arduino Starter Kit Parts required: - 10 kilohm resistor - six 220 ohm resistors - six LEDs - tilt switch created 13 Sep 2012 by Scott Fitzgerald http://www.arduino.cc/starterKit This example code is part of the public domain. */ // named constant for the switch pin const int switchPin = 8; unsigned long previousTime = 0; // store the last time an LED was updated int switchState = 0; // the current switch state int prevSwitchState = 0; // the previous switch state int led = 2; // a variable to refer to the LEDs // 600000 = 10 minutes in milliseconds long interval = 600000; // interval at which to light the next LED void setup() { // set the LED pins as outputs for (int x = 2; x < 8; x++) { pinMode(x, OUTPUT); } // set the tilt switch pin as input pinMode(switchPin, INPUT); } void loop() { // store the time since the Arduino started running in a variable unsigned long currentTime = millis(); // compare the current time to the previous time an LED turned on // if it is greater than your interval, run the if statement if (currentTime - previousTime > interval) { // save the current time as the last time you changed an LED previousTime = currentTime; // Turn the LED on digitalWrite(led, HIGH); // increment the led variable // in 10 minutes the next LED will light up led++; if (led == 7) { // the hour is up } } // read the switch value switchState = digitalRead(switchPin); // if the switch has changed if (switchState != prevSwitchState) { // turn all the LEDs low for (int x = 2; x < 8; x++) { digitalWrite(x, LOW); } // reset the LED variable to the first one led = 2; //reset the timer previousTime = currentTime; } // set the previous switch state to the current state prevSwitchState = switchState; }