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I'm fairly new to Arduino and am trying to use a push button to toggle an LED on and off using a momentary press of the button. This code is lifted straight off the tutorial on the Arduino website but is not working for me. It seems to send the LED on a loop - switching between on and off by itself, and pressing the button pauses the cycle.

Any ideas as to why it is doing that?

J

int buttonPin = 2;         // the number of the input pin
int ledPin = 13;       // the number of the output pin

int state = HIGH;      // the current state of the output pin
int reading;           // the current reading from the input pin
int previous = LOW;    // the previous reading from the input pin

// the follow variables are long's because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long time = 0;         // the last time the output pin was toggled
long debounce = 200;   // the debounce time, increase if the output flickers

void setup()
{
  pinMode(buttonPin, INPUT);
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);

}

void loop()
{
 
 
  reading = digitalRead(buttonPin);

  // if the input just went from LOW and HIGH and we've waited long enough
  // to ignore any noise on the circuit, toggle the output pin and remember
  // the time
if (reading == HIGH  && previous == LOW && millis() - time > debounce) {
  if (state == HIGH)
    state = LOW;
  else 
    state = HIGH;
time = millis();    
}

else 
  if (state == LOW)
    state = LOW;
  else 
    state = HIGH;
  digitalWrite(ledPin, state);
 //Serial.println(buttonPin);
  // 
 Serial.println(reading);
previous = reading;
} 

I'm fairly new to Arduino and am trying to use a push button to toggle an LED on and off using a momentary press of the button. This code is lifted straight off the tutorial on the Arduino website but is not working for me. It seems to send the LED on a loop - switching between on and off by itself, and pressing the button pauses the cycle.

Any ideas as to why it is doing that?

int buttonPin = 2;         // the number of the input pin
int ledPin = 13;       // the number of the output pin

int state = HIGH;      // the current state of the output pin
int reading;           // the current reading from the input pin
int previous = LOW;    // the previous reading from the input pin

// the follow variables are long's because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long time = 0;         // the last time the output pin was toggled
long debounce = 200;   // the debounce time, increase if the output flickers

void setup()
{
  pinMode(buttonPin, INPUT);
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);

}

void loop()
{
 
 
  reading = digitalRead(buttonPin);

  // if the input just went from LOW and HIGH and we've waited long enough
  // to ignore any noise on the circuit, toggle the output pin and remember
  // the time
if (reading == HIGH  && previous == LOW && millis() - time > debounce) {
  if (state == HIGH)
    state = LOW;
  else 
    state = HIGH;
time = millis();    
}

else 
  if (state == LOW)
    state = LOW;
  else 
    state = HIGH;
  digitalWrite(ledPin, state);
 //Serial.println(buttonPin);
  // 
 Serial.println(reading);
previous = reading;
} 

int buttonPin = 2; // the number of the input pin int ledPin = 13; // the number of the output pin

int state = HIGH; // the current state of the output pin int reading; // the current reading from the input pin int previous = LOW; // the previous reading from the input pin

// the follow variables are long's because the time, measured in miliseconds, // will quickly become a bigger number than can be stored in an int. long time = 0; // the last time the output pin was toggled long debounce = 200; // the debounce time, increase if the output flickers

void setup() { pinMode(buttonPin, INPUT); pinMode(ledPin, OUTPUT); Serial.begin(9600);

}

void loop() {

reading = digitalRead(buttonPin);

// if the input just went from LOW and HIGH and we've waited long enough // to ignore any noise on the circuit, toggle the output pin and remember // the time if (reading == HIGH && previous == LOW && millis() - time > debounce) { if (state == HIGH) state = LOW; else state = HIGH; time = millis();
}

else if (state == LOW) state = LOW; else state = HIGH; digitalWrite(ledPin, state); //Serial.println(buttonPin); // Serial.println(reading); previous = reading; }

int buttonPin = 2;         // the number of the input pin
int ledPin = 13;       // the number of the output pin

int state = HIGH;      // the current state of the output pin
int reading;           // the current reading from the input pin
int previous = LOW;    // the previous reading from the input pin

// the follow variables are long's because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long time = 0;         // the last time the output pin was toggled
long debounce = 200;   // the debounce time, increase if the output flickers

void setup()
{
  pinMode(buttonPin, INPUT);
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);

}

void loop()
{
 
 
  reading = digitalRead(buttonPin);

  // if the input just went from LOW and HIGH and we've waited long enough
  // to ignore any noise on the circuit, toggle the output pin and remember
  // the time
if (reading == HIGH  && previous == LOW && millis() - time > debounce) {
  if (state == HIGH)
    state = LOW;
  else 
    state = HIGH;
time = millis();    
}

else 
  if (state == LOW)
    state = LOW;
  else 
    state = HIGH;
  digitalWrite(ledPin, state);
 //Serial.println(buttonPin);
  // 
 Serial.println(reading);
previous = reading;
}