ESP32 - Motion Sensor - Piezo Buzzer
This tutorial instructs you how to use ESP32 with HC-SR501 motion sensor and Piezo Buzzer. In detail:
- ESP32 automatically makes sound if the motion is detected, and stops making sound if otherwise
- ESP32 automatically makes a melody of song if the motion is detected, and stops making sound if otherwise
Hardware Used In This Tutorial
1 | × | ESP-WROOM-32 Dev Module | |
1 | × | Micro USB Cable | |
1 | × | HC-SR501 Motion Sensor | |
1 | × | Piezo Buzzer | |
1 | × | Jumper Wires | |
1 | × | (Optional) 5V Power Adapter | |
1 | × | (Optional) DC Power Jack | |
1 | × | (Optional) ESP32 Screw Terminal Adapter |
One of the following breadboard:
1 | × | Full-sized 830-Point Breadboard | |
1 | × | Half-sized 400-point Breadboard | |
1 | × | Mini-sized 170-point Breadboard | |
1 | × | All-sized Breadboard Kit |
Introduction to Piezo Buzzer and Motion Sensor
We have specific tutorials about piezo buzzer and motion sensor. Each tutorial contains detailed information and step-by-step instructions about hardware pinout, working principle, wiring connection to ESP32, ESP32 code... Learn more about them at the following links:
Wiring Diagram
The wiring diagram with power supply from USB cable

This image is created using Fritzing. Click to enlarge image
The wiring diagram with power supply from 5v adapter

This image is created using Fritzing. Click to enlarge image
Initial Setting
Detection Range Adjuster | Fully screw it in the clockwise direction. |
Time Delay Adjuster | Fully screw it in the anti-clockwise direction. |
Repeat Trigger Selector | Put jumper like the below image. |

ESP32 Code - Simple Sound
Quick Instructions
- If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
- Do the wiring as above image.
- Connect the ESP32 board to your PC via a micro USB cable
- Open Arduino IDE on your PC.
- Select the right ESP32 board (e.g. ESP32 Dev Module) and COM port.
- Copy the above code and paste it to Arduino IDE.
- Compile and upload code to ESP32 board by clicking Upload button on Arduino IDE
- Move your hand in front of sensor
- Listen to piezo buzzer's sound
Line-by-line Code Explanation
The above ESP32 code contains line-by-line explanation. Please read the comments in the code!
ESP32 Code - Melody
Quick Instructions
- If this is the first time you use ESP32, see how to setup environment for ESP32 on Arduino IDE.
- Copy the above code and paste it to Arduino IDE.
- Create the pitches.h file On Arduino IDE:

- Either click on the button just below the serial monitor icon and choose "New Tab", or use Ctrl+Shift+N.
- Give file's name "pitches.h" and click "OK" button
- Copy the below code and paste it to that file.
- Compile and upload code to ESP32 board by clicking Upload button on Arduino IDE
- Move your hand in front of sensor
- Listen to piezo buzzer's melody
Line-by-line Code Explanation
The above ESP32 code contains line-by-line explanation. Please read the comments in the code!
Video Tutorial
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WARNING
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