Note

Hello, welcome to the SunFounder Raspberry Pi & Arduino & ESP32 Enthusiasts Community on Facebook! Dive deeper into Raspberry Pi, Arduino, and ESP32 with fellow enthusiasts.

Why Join?

  • Expert Support: Solve post-sale issues and technical challenges with help from our community and team.

  • Learn & Share: Exchange tips and tutorials to enhance your skills.

  • Exclusive Previews: Get early access to new product announcements and sneak peeks.

  • Special Discounts: Enjoy exclusive discounts on our newest products.

  • Festive Promotions and Giveaways: Take part in giveaways and holiday promotions.

👉 Ready to explore and create with us? Click [here] and join today!

3.1 Make the Buzzer Beep!

In this lesson, we will learn how to make a buzzer beep using the Raspberry Pi Pico 2. A buzzer is a digital output device, just like an LED, and it’s very simple to control. We’ll use an active buzzer for this project, which generates sound when it receives a signal.

What is an Active Buzzer?

An active buzzer has an internal oscillator that makes it easier to use. You only need to send a signal to the buzzer to make it beep—no complex frequency control is required. This is different from a passive buzzer, which requires an external signal to generate sound.

img_buzzer

What You’ll Need

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name

ITEMS IN THIS KIT

LINK

Newton Lab Kit

450+

Newton Lab Kit

You can also buy them separately from the links below.

SN

COMPONENT

QUANTITY

LINK

1

Raspberry Pi Pico 2

1

BUY

2

Micro USB Cable

1

3

Breadboard

1

BUY

4

Jumper Wires

Several

BUY

5

Transistor

1(S8050)

BUY

6

Resistor

1(1KΩ)

BUY

7

Active Buzzer

1

Circuit Diagram

sch_buzzer

In this circuit, the buzzer is powered through a transistor (S8050 NPN). The transistor amplifies the current, making the buzzer sound louder than if it were connected directly to the Pico.

Here’s what happens:

  • GP15 outputs a high signal to control the transistor.

  • When the transistor is activated, it allows current to flow through the buzzer, making it beep.

A 1kΩ resistor is used to limit the current to protect the transistor.

Wiring Diagram

Make sure you are using the active buzzer. You can tell it’s the correct one by looking for the sealed back (as opposed to the exposed PCB, which is a passive buzzer).

img_buzzer

wiring_beep

Writing the Code

Let’s write a simple MicroPython program to control the buzzer.

Note

  • Open the 3.1_beep.py from newton-lab-kit/micropython or copy the code into Thonny, then click “Run” or press F5.

  • Ensure the correct interpreter is selected: MicroPython (Raspberry Pi Pico).COMxx.

import machine
import utime

# Initialize the buzzer pin (GP15)
buzzer = machine.Pin(15, machine.Pin.OUT)

while True:
    # Loop to beep the buzzer 4 times
    for i in range(4):
        buzzer.value(1)  # Turn the buzzer on
        utime.sleep(0.3)  # Wait for 0.3 seconds
        buzzer.value(0)  # Turn the buzzer off
        utime.sleep(0.3)  # Wait for 0.3 seconds
    utime.sleep(1)  # Longer pause before the next cycle

When the code is running, you should hear:

  • The buzzer will beep 4 times in a row, with a 0.3-second pause between each beep.

  • After the 4 beeps, there will be a longer 1-second pause before the cycle repeats.

Explanation of the Code

  1. Buzzer Initialization:

    • buzzer = machine.Pin(15, machine.Pin.OUT): Initializes GP15 as the output pin to control the buzzer.

  2. Main Loop:

    • The while True: loop ensures the code runs indefinitely.

    • Inside the loop, the buzzer is turned on (buzzer.value(1)) and off (buzzer.value(0)) four times, each with a 0.3-second delay.

    • After the four beeps, there is a 1-second pause before the cycle repeats.

Experimenting Further

  • Change the Beep Duration: Adjust the utime.sleep(0.3) values to make the beeps longer or shorter.

  • Vary the Number of Beeps: Change the number of iterations in the loop to make the buzzer beep more or fewer times.

  • Add Button Control: Try connecting a button to GP14, and modify the code to beep only when the button is pressed.

Conclusion

In this lesson, you learned how to control an active buzzer using a transistor and the Raspberry Pi Pico 2. You now have a basic understanding of how to use a digital output device to create sound in your projects. The same principles can be applied to other output devices, like LEDs, motors, and more.