Raspberry Pi - Door Sensor - Piezo Buzzer

This tutorial instructs you how to use Raspberry Pi and door sensor to trigger piezo buzzer. In detail::

Hardware Preparation

1×Raspberry Pi 4 Model B
1×Door Sensor
1×Piezo Buzzer
1×Breadboard
1×Jumper Wires
1×(Optional) Screw Terminal Adapter for Raspberry Pi

Or you can buy the following sensor kit:

1×DIYables Sensor Kit 30 types, 69 units
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Overview of Piezo Buzzer and Door Sensor

If you are unfamiliar with piezo buzzer and door sensor, including their pinout, functionality, and programming, the following tutorials can help:

Wiring Diagram

The wiring diagram between Raspberry Pi and Door Sensor Piezo Buzzer

This image is created using Fritzing. Click to enlarge image

Raspberry Pi Code - Simple Sound

In this section, we will learn how to use a piezo buzzer to produce a simple sound when the door is open using Raspberry Pi.

Detailed Instructions

  • Make sure you have Raspbian or any other Raspberry Pi compatible operating system installed on your Pi.
  • Make sure your Raspberry Pi is connected to the same local network as your PC.
  • Make sure your Raspberry Pi is connected to the internet if you need to install some libraries.
  • If this is the first time you use Raspberry Pi, See how to set up the Raspberry Pi
  • Connect your PC to the Raspberry Pi via SSH using the built-in SSH client on Linux and macOS or PuTTY on Windows. See to how connect your PC to Raspberry Pi via SSH.
  • Make sure you have the RPi.GPIO library installed. If not, install it using the following command:
sudo apt-get update sudo apt-get install python3-rpi.gpio
  • Create a Python script file door_sensor_buzzer.py and add the following code:
# This Raspberry Pi code was developed by newbiely.com # This Raspberry Pi code is made available for public use without any restriction # For comprehensive instructions and wiring diagrams, please visit: # https://newbiely.com/tutorials/raspberry-pi/raspberry-pi-door-sensor-piezo-buzzer import RPi.GPIO as GPIO import time # Set the GPIO mode (BCM or BOARD) GPIO.setmode(GPIO.BCM) # Define the GPIO pin number to which the buzzer is connected BUZZER_PIN = 20 # Define the GPIO pin number to which the door sensor is connected DOOR_SENSOR_PIN = 18 # Set up the GPIO pins GPIO.setup(DOOR_SENSOR_PIN, GPIO.IN, pull_up_down=GPIO.PUD_UP) # Input with pull-up resistor GPIO.setup(BUZZER_PIN, GPIO.OUT) # Output try: while True: door_state = GPIO.input(DOOR_SENSOR_PIN) if door_state == GPIO.HIGH: print("The door is open") GPIO.output(BUZZER_PIN, GPIO.HIGH) # Turn the buzzer on else: print("The door is closed") GPIO.output(BUZZER_PIN, GPIO.LOW) # Turn the buzzer off # Add a slight delay to debounce the door sensor (optional) time.sleep(0.1) # Allow the user to stop the buzzer by pressing Ctrl+C except KeyboardInterrupt: GPIO.output(BUZZER_PIN, GPIO.LOW) # Turn off the buzzer GPIO.cleanup()
  • Save the file and run the Python script by executing the following command in the terminal:
python3 door_sensor_buzzer.py
  • Bring the magnet close to the reed switch, then move it away.
  • Listen to the sound of the piezo buzzer.

The script runs in an infinite loop continuously until you press Ctrl + C in the terminal.

Code Explanation

Check out the line-by-line explanation contained in the comments of the source code!

Raspberry Pi plays the melody of the song

In this section, we will make the Raspberry Pi trigger the piezo buzzer to play the song "Jingle Bells" when the door is open.

Detailed Instructions

  • Create a Python script file door_buzzer_Jingle_Bells.py and add the following code:
# This Raspberry Pi code was developed by newbiely.com # This Raspberry Pi code is made available for public use without any restriction # For comprehensive instructions and wiring diagrams, please visit: # https://newbiely.com/tutorials/raspberry-pi/raspberry-pi-door-sensor-piezo-buzzer import RPi.GPIO as GPIO import time # Set the GPIO mode (BCM or BOARD) GPIO.setmode(GPIO.BCM) # Define the GPIO pin number to which the buzzer is connected BUZZER_PIN = 20 # Define the GPIO pin number to which the door sensor is connected DOOR_SENSOR_PIN = 18 # Set up the GPIO pins GPIO.setup(BUZZER_PIN, GPIO.OUT) GPIO.setup(DOOR_SENSOR_PIN, GPIO.IN, pull_up_down=GPIO.PUD_UP) # Constants for note names and their corresponding frequencies C4 = 261 D4 = 293 E4 = 329 F4 = 349 G4 = 392 A4 = 440 B4 = 493 # Dictionary to map numeric values to note names note_names = { C4: "C4", D4: "D4", E4: "E4", F4: "F4", G4: "G4", A4: "A4", B4: "B4", } # List of notes in the "Jingle Bells" melody melody = [ E4, E4, E4, E4, E4, E4, E4, G4, C4, D4, E4, F4, F4, F4, F4, F4, E4, E4, E4, E4, E4, D4, D4, E4, D4, G4 ] # List of note durations (in milliseconds) note_durations = [ 200, 200, 400, 200, 200, 400, 200, 200, 200, 200, 200, 200, 200, 400, 200, 200, 200, 200, 200, 200, 200, 200, 200, 400, 200, 200 ] # Pause duration between notes (in milliseconds) pause_duration = 300 def play_tone(pin, frequency, duration): # Calculate the period based on the frequency period = 1.0 / frequency # Calculate the time for half of the period half_period = period / 2.0 # Calculate the number of cycles for the given duration cycles = int(duration / period) for _ in range(cycles): # Set the GPIO pin to HIGH GPIO.output(pin, GPIO.HIGH) # Wait for half of the period time.sleep(half_period) # Set the GPIO pin to LOW GPIO.output(pin, GPIO.LOW) # Wait for the other half of the period time.sleep(half_period) def play_jingle_bells(): for i in range(len(melody)): note_duration = note_durations[i] / 1000.0 note_freq = melody[i] note_name = note_names.get(note_freq, "Pause") print(f"Playing {note_name} (Frequency: {note_freq} Hz) for {note_duration} seconds") play_tone(BUZZER_PIN, note_freq, note_duration) time.sleep(pause_duration / 1000.0) GPIO.output(BUZZER_PIN, GPIO.LOW) try: while True: door_state = GPIO.input(DOOR_SENSOR_PIN) if door_state == GPIO.HIGH: play_jingle_bells() # Allow the user to stop the buzzer by pressing Ctrl+C except KeyboardInterrupt: GPIO.output(BUZZER_PIN, GPIO.LOW) GPIO.cleanup()
  • Save the file and run the Python script by executing the following command in the terminal:
python3 door_buzzer_Jingle_Bells.py
  • Move the magnet far from the reed switch of door sensor to simulate the door open.
  • Hear the tune of the piezo buzzer.

Code Explanation

Take a look at the line-by-line explanation in the comments section of the source code!

Video Tutorial