Buzzer / Piezo

Active Buzzer Module

Self-oscillating buzzer that beeps with just a single HIGH signal — no PWM required.

A buzzer with a built-in oscillator — just apply power to get a fixed-tone beep, no PWM signal generation required.

Specifications

Operating voltage	3V - 5V DC (5V typical on breakout modules)
Current draw	~25-30mA
Tone	Fixed frequency, ~2-4kHz — set by the buzzer's internal oscillator, not by your code
Control	Digital HIGH/LOW only — a plain digitalWrite() is enough, no tone() or PWM needed

Pinout

Pin	Name	Description
1	VCC	Power, 3V-5V DC
2	GND	Ground
3	I/O	Signal input — HIGH turns the tone on, LOW turns it off

Easy to tell apart from a passive buzzer without a multimeter: tap 5V straight to the pin briefly — an active buzzer beeps immediately, a passive one just clicks.

Board Integration

Wiring

Component pin	Board pin	Note
VCC	5V
GND	GND
I/O	D8	Any digital pin works — this is a plain HIGH/LOW signal, not PWM

Code

C++

Notes

This is an active buzzer (built-in oscillator) — do not use tone(), which is for passive buzzers that need a driven frequency. A plain digitalWrite HIGH/LOW is all it needs, and driving it with tone() will not change the pitch.