Buzzer music: Simple melodies with the Pi Pico

Buzz It, Baby!

Article from Issue 297/2025

Author(s): Bernhard Bablok

Use the buzzer to have your MCU play small wake-up melodies, signals, or music to accompany LED animations. The sound might not be a feast for the ears, but it does give your projects a great retro feel.

Every PC has at least a small beeper for signal tones. In the case of microcontrollers, you need to retrofit a buzzer to do this, but buzzers are too good for just outputting beeps. They are available for a small amount from the typical marketplaces, and you can choose between two basic types: active and passive. The active relies on a built-in oscillator to generate sound and only require two pins, while you need to feed a PWM signal to the passive. Besides voltage and earth, they require another pin for the signal.

The buzzers themselves look like small black pots with two pins (Figure 1, center and right). For active buzzers, you just need the component itself, but for passive buzzers, it makes sense to use a breakout with the required circuitry (Figure 1, left). There are also breakouts for active buzzers with three pins, but one of them is not assigned in this case. When purchasing, you can use the designation as a guide: Passive buzzers will be known as KY-006 or HW-508, while an active variant often has KY-012 in its name.