Lesson 5 Buzzer

Share for us


You can use a buzzer whenever you want to make some noise.


– 1 * SunFounder Uno board

– 1 * Breadboard

– 1 * USB data cable

– 1 * Buzzer (Active)

– Jumper wires


As a type of electronic buzzer with integrated structure, buzzers, which are supplied by DC power, are widely used in computers, printers, photocopiers, alarms, electronic toys, automotive electronic devices, telephones, timers and other electronic products for voice devices. Buzzers can be categorized as active and passive ones (see the following picture). Turn the pins of two buzzers face up, and the one with a green circuit board is a passive buzzer, while the other enclosed with a black tape is an active one.

The difference between an active buzzer and a passive buzzer is:

An active buzzer has a built-in oscillating source, so it will make sounds when electrified. But a passive buzzer does not have such source, so it will not tweet if DC signals are used; instead, you need to use square waves whose frequency is between 2K and 5K to drive it. The active buzzer is often more expensive than the passive one because of multiple built-in oscillating circuits.

In this experiment, we use the active buzzer.

Experimental Procedures

Step 1: Build the circuit

The schematic diagram

Step 2: Program (Please refer to the example code in LEARN -> Get Tutorial on our website)

Step 3: Compile the code

Step 4: Upload the sketch to the SunFounder Uno board

Now, you should hear the buzzer make sounds.


// Buzzer
// buzzer make sounds
int buzzer = 12;//the pin of the active buzzer
void setup()
  pinMode(buzzer,OUTPUT);//initialize the buzzer pin as an output
void loop()
  unsigned char i; //define a variable
    //output an frequency
      delay(1);//wait for 1ms
      delay(1);//wait for 1ms
    //output another frequency
      delay(2);//wait for 2ms
      delay(2);//wait for 2ms