Active buzzer on an Arduino Uno

// Active buzzer: a buzzer with its own oscillator, switched on and off.
//
//   pin 12  the buzzer's long leg (+), the short leg to GND
//
// An active buzzer has the tone generator built in. Give it 5 V and it sounds;
// take the 5 V away and it stops. So the sketch never makes a tone itself: it
// only decides when the buzzer is on. Here that is a run of quick beeps, then
// a run of slower ones, over and over.
//
// The other buzzer in most kits is passive: it has no oscillator, stays
// silent on a steady 5 V, and needs tone() to make the sound wave for it.

const int BUZZER = 12;

void beeps(int count, int onMs, int offMs) {
  for (int i = 0; i < count; i++) {
    digitalWrite(BUZZER, HIGH);
    delay(onMs);
    digitalWrite(BUZZER, LOW);
    delay(offMs);
  }
}

void setup() {
  pinMode(BUZZER, OUTPUT);
  Serial.begin(9600);
  Serial.println("Mokxi Uno: active buzzer");
}

void loop() {
  Serial.println("quick beeps");
  beeps(8, 60, 60);
  Serial.println("slow beeps");
  beeps(4, 250, 250);
  delay(500);
}