Active Buzzer

What it is

A piezo element with an oscillator built into the package. Give it power and it makes its one note; take the power away and it stops.

That single fixed pitch is the difference from TK37, and it is the reason to choose this one. For an alarm, a keypress confirmation or a "something is wrong" beep you do not want a melody — you want one line of code and a noise. It also frees the timer that tone() would otherwise claim.

It is loud. Louder than you expect on a desk at two in the morning, and there is no volume control: PWM changes the duty cycle, not the amplitude, and mostly just makes it sound worse. If you need it quieter, put tape over the hole — which sounds like a joke and is what everyone actually does.

Pinout

• GND (negative): Like the negative terminal (-) of a battery, connect to the control board's GND
• VCC (positive): Like the positive terminal (+) of a battery, connect to the control board's 3.3V or 5V (this module supports both 3.3V and 5V)
• NC (no connection): No actual circuit connection, included for unified interface, can be left unconnected
• SIGNAL (signal input): Pin to control buzzer, connect to the control board's digital pin (e.g. Arduino D3 or Pico GPIO 0)
  • When HIGH (HIGH/1) is input, buzzer emits sound
  • When LOW (LOW/0) is input, buzzer stops
  • Can only emit fixed frequency sound, cannot change pitch

Wiring

1. GND → Control board GND
2. VCC → Control board 3.3V or 5V
3. SIGNAL → Control board digital pin (use the pin defined in your program)

Example

// Pin number: change this to match your wiring
#define BUZZER_PIN 3  // Arduino digital pin connected to SIGNAL (e.g. D3)

void setup() {
  // Initialize pin mode
  pinMode(BUZZER_PIN, OUTPUT);
  
  // Start serial for debugging (9600 baud)
  Serial.begin(9600);
  
  Serial.println("Active buzzer program started");
}

void loop() {
  // Buzzer on for 0.5 seconds
  digitalWrite(BUZZER_PIN, HIGH);  // Turn on buzzer
  Serial.println("Buzzer on");
  delay(500);  // Wait 0.5 seconds
  
  // Buzzer off for 0.5 seconds
  digitalWrite(BUZZER_PIN, LOW);   // Turn off buzzer
  Serial.println("Buzzer off");
  delay(500);  // Wait 0.5 seconds
}

# Import required modules
from machine import Pin  # GPIO control
import time              # For delay (time.sleep)

# Pin number: change this to match your wiring
BUZZER_PIN = 0  # GPIO connected to SIGNAL (e.g. GPIO 0)

# Create Pin object, set as output mode
buzzer = Pin(BUZZER_PIN, Pin.OUT)

print("Active buzzer program started")

# Main loop: runs forever
while True:
    # Buzzer on for 0.5 seconds
    buzzer.on()  # Turn on buzzer
    print("Buzzer on")
    time.sleep(0.5)  # Wait 0.5 seconds
    
    # Buzzer off for 0.5 seconds
    buzzer.off()  # Turn off buzzer
    print("Buzzer off")
    time.sleep(0.5)  # Wait 0.5 seconds