Name: Multi-Function Shield: Beeper
Uploaded: 2026-09-14T13:40:46.801Z
Description: Drive the on-board buzzer directly, then with the library's beep patterns.

Active, not passive

The buzzer on this shield is an active buzzer on pin 3: it takes a plain HIGH or LOW and plays one fixed pitch. LOW makes noise, HIGH is silent. You cannot play tunes with it, but it is perfect for alarms and alerts.

Two ways to use it

Direct. digitalWrite(BEEPER_PIN, LOW) while a button is held, HIGH when released. That is what loop() does below.
Library. MFS.beep() gives a short beep. With arguments, MFS.beep(on, off, cycles, loops, loopDelay) builds patterns. Every time value is in units of 10 ms, so MFS.beep(5, 5, 4, 3, 50) means: on 50 ms, off 50 ms, four times, repeated three times, with 500 ms between repeats.

The library needs Timer1.initialize() followed by MFS.initialize(&Timer1) in setup(). The TimerOne library is what lets the beeper pattern run in the background while your loop keeps going.

Beeper: direct and library patterns

#include <TimerOne.h>
#include <Wire.h>
#include <MultiFuncShield.h>

// BUTTON_1_PIN (A1) and BEEPER_PIN (3) come from MultiFuncShield.h

void setup() {
  pinMode(BUTTON_1_PIN, INPUT);
  pinMode(BEEPER_PIN, OUTPUT);
  digitalWrite(BEEPER_PIN, HIGH);   // HIGH = silent

  Timer1.initialize();
  MFS.initialize(&Timer1);

  MFS.beep();                       // one short beep
  delay(1000);

  // on 50 ms, off 50 ms, 4 cycles, repeated 3 times, 500 ms between repeats
  MFS.beep(5, 5, 4, 3, 50);
}

void loop() {
  // Hold button 1 to sound the buzzer directly
  if (digitalRead(BUTTON_1_PIN) == 0) {
    digitalWrite(BEEPER_PIN, LOW);  // sound
  } else {
    digitalWrite(BEEPER_PIN, HIGH); // silent
  }
}