My ciruit: enter image description here

My code:

// Pin 13 has a LED connected on most Arduino boards.
// give it a name:
int led = 13;
const int buttonPin = 2;

// the setup routine runs once when you press reset:
void setup() {
  // initialize the digital pin as an output.
  pinMode(led, OUTPUT);
  pinMode(buttonPin, INPUT_PULLUP);

// the loop routine runs over and over again forever:
void loop() 
  bool buttonState = digitalRead(buttonPin);
  while (buttonState == LOW)
   digitalWrite(led, HIGH);   // turn the LED on (HIGH is the voltage level)
   delay(1000);               // wait for a second
   digitalWrite(led, LOW);    // turn the LED off by making the voltage LOW
   delay(1000);               // wait for a second

What I wish to do, is that when the button is pressed, and the Led's start to blink, I want the piezo buzzer to make a sound. I have never worked with them before so I am having troubles getting results. Is it that the setup is wrong or the code needs extra lines than just the tone(12,260); that I added?

  • General advice: get one thing working at a time. I don't think your button/flash code does what you want, even before you add the buzzer.
    – Mark Smith
    Feb 28, 2017 at 7:43
  • @MarkSmith Is this reference towards my previous question?
    – Utsav
    Feb 28, 2017 at 8:00
  • No, to this one.
    – Mark Smith
    Feb 28, 2017 at 8:10
  • Well my whole point of this project is to implement an alarm system. currently it works with the button acting as the alarm switch, led's as the lights and piezo for the sound. From the answer below, I have done this, however I couldn't understand any of the answers from my previous question (arduino.stackexchange.com/questions/35177/…) that allowed me to disable the alarm. That is really the only problem I am facing currently.
    – Utsav
    Feb 28, 2017 at 8:14
  • @Utsav Some issues will disappear if you stop using buttonState and start using digitalRead everywhere instead. You need current state of pin, not the state loaded looooong time ago. The buttonState won't magically change a state without any assigment into it!
    – KIIV
    Feb 28, 2017 at 8:22

1 Answer 1


Both the code and the circuit have problems.

In the code:

• If the while (buttonState == LOW) loop is ever entered, it will never be left, because buttonState, the controlling variable, does not change within the loop.

The simplest fix is to remove the line bool buttonState = digitalRead(buttonPin); and replace while (buttonState == LOW) with while (!digitalRead(buttonPin)), which says to loop while digitalRead(buttonPin) is not true; ie, while it is false, or low.

• The empty braces, { } at the end of the while loop are superfluous and should be deleted.

In the circuit diagram:

• Neither of the leads of the buzzer is attached to the Arduino circuit, so it won't make any sound. Note, tone(12,260); tells the Arduino to use pin 12 for tone output.

To fix this problem, run a wire from pin 12 to one side of the buzzer, and a wire to ground for the other side of the buzzer.

• A blue LED in series with a red LED might or might not turn on when supplied with 5 V. For example, if the red LED takes 1.8 V and the blue LED takes 3.3 V to turn on, the 5.1 V total is too high to be turned on by 5 V signals. Remove one of the two LEDs, and move the wires to the other LED to complete a circuit.


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