How to use a Buzzer

A buzzer is a small component to add sound features to the embedded system. They can be used to raise an alarm, observe and note the status of equipment, indicate commands, enhance user interactions, etc. It comes with 2-pin and can be easily plugged on a breadboard.

Buzzers are divided into two kinds, one is active and another is passive. Both types of buzzers are polarized, so check which terminal is positive and which terminal is negative before connecting it to the circuit.


How to distinguish between a passive buzzer and an active buzzer?

Active Buzzer
Passive Buzzer

There are several ways to distinguish passive buzzers and active buzzers.

  • The most simple method is to watch their different appearances. If you can see a drive board, it is a passive buzzer. If the buzzer is completely covered by black adhesive, it is an active buzzer.
  • Another method. Using a battery with a piece of electric wire, separately touch the connection terminals of the buzzer. If the buzzer makes a sound like "Chi" with every touch, it is a passive buzzer. If it just makes a sound for one time or is soundless, it is an active buzzer.
  • Controllable sound is one feature of the passive buzzer. It can make sounds in different frequencies. However, it must be driven by a square wave and then will make a sound.
  • While an active buzzer doesn't need a square wave, it will make a sound when DC power is supplied. That is because there is an oscillator in the active buzzer while no oscillator in the passive buzzer.
  • Most passive buzzers are small in size. In the market, there are more passive buzzers than active buzzers. The active buzzer is more expensive than the passive buzzer.