Debounce

Parts

-Arduino microcontroller and carrier board

-LiPo battery

-Switch button

-Resistor

-3 Jumper wires

Prepare the breadboard

Program the Microcontroller

For more information: Arduino Debounce Tutorial

/**
 * @file: Debounce
 * @date: 4/5/2011
 *

* @DESCRIPTION

 * Each time the input pin goes from LOW to HIGH (e.g. because of a push-button
 * press), the output pin is toggled from LOW to HIGH or HIGH to LOW.  There's
 * a minimum delay between toggles to debounce the circuit (i.e. to ignore noise).  
 *
 * http://www.arduino.cc/en/Tutorial/Debounce
 *
**/

#define buttonPin 2

int buttonState = 0;             // the current reading from the input pin

int lastButtonState = LOW; // the previous reading from the input pin

long lastDebounceTime = 0; // the last time the output pin was toggled

const long debounceDelay = 50; // the debounce time; increase if the output flickers

//--- Function: Setup ()

void setup()

{

pinMode(buttonPin, INPUT);

}
//--- Function: Setup ()

void loop()

{

int reading = digitalRead(buttonPin); // read the state of the switch 

  // If the switch changed, due to noise or pressing:

if (reading != lastButtonState)

  {

lastDebounceTime = millis(); // reset the debouncing timer

  }

if ((millis() - lastDebounceTime) > debounceDelay)

  {
    buttonState = reading;         //    actual current state
  }

// save the reading. Next time through the loop, it'll be the lastButtonState:

  lastButtonState = reading;
}

Code from Lecture

int reading = 0;
int buttonState = 0;
int lastButtonState = LOW;
int lastReading = LOW;
long lastDebounceTime = 0;

#define buttonPin 3

void setup()
{
    pinMode(buttonPin, INPUT);
    Serial.begin(9600); delay(25);
}
void loop()
{
    reading = digitalRead(buttonPin);
    if (reading != lastReading)
    {
        lastDebounceTime = millis();
    }
    if ((millis() - lastDebounceTime) > 50)
    {
        buttonState = reading;
        if (buttonState&(!lastButtonState))
        {
            Serial.println("button press");

}

     }
        lastButtonState = buttonState;
        lastReading = reading;
}