BlueGraysArduino · ESP32 · Pico
#13Beginner

Using a Buzzer

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Using a Buzzer
Basic project that uses the buzzer to emit a sound at a specific frequency and interval. Teaches the use of tone() and noTone() functions.

Video

Circuit Diagram

Using a Buzzer - Circuit

Source Code

Arduino (C++)
1// ─────────────────────────────────────────
2//   BlueGrays · bluegrays.com
3//   Using a Buzzer
4// ─────────────────────────────────────────
5// The buzzer beeps at 400 Hz for 0.3 s, stays silent for 0.3 s and keeps
6// repeating. Shows how to use tone() and noTone().
7//
8// Pins:
9//   D7 -> Buzzer + (other leg to GND)
10
11int frequency = 400;   // Tone frequency (Hz)
12int buzzerPin = 7;     // Buzzer output pin
13
14void setup() {
15  // tone() sets the pin as an output itself
16}
17
18void loop() {
19  tone(buzzerPin, frequency);   // Start the 400 Hz tone
20  delay(300);
21  noTone(buzzerPin);            // Stop the sound
22  delay(300);
23}
24

FAQ

What is the difference between an active and a passive buzzer?▾

An active buzzer contains an oscillator; it produces a constant tone only when a voltage is applied. A passive buzzer requires an external frequency source; it can play different notes using the `tone()` function. Passive buzzers are required for melody projects.

How do you use the tone() function?▾

tone(pin, frequency) plays a sound at the specified frequency; noTone(pin) silences it. A duration can also be specified using the format tone(pin, frequency, duration). For example, 440 Hz is the note A.

The volume is very low. How can I turn it up?▾

The Arduino pin drives the buzzer with a limited current. For a louder sound, you can drive the buzzer through an NPN transistor (e.g., BC547) or choose a configuration that doesn't block the buzzer's hole.

Will using `tone()` cause problems on the other pins?▾

In Uno, the `tone()` function uses Timer2; therefore, PWM (analogWrite) does not work properly on pins 3 and 11 while it is playing. If you need PWM at the same time, select different pins.

Using a Buzzer | BlueGrays