Raspberry Pi - Potentiometer Piezo Buzzer
This tutorial instructs you how to use Raspberry Pi and potentiometer to control piezo buzzer. In detail:
- Raspberry Pi determines if the potentiometer's analog value is above or below a threshold, and make sound accordingly
- Raspberry Pi determines if the potentiometer's output voltage is above or below a threshold, and make sound accordingly
- If the potentiometer's output voltage is greater than a threshold, Raspberry Pi can also play a melody of a song
Hardware Preparation
| 1 | × | Raspberry Pi 4 Model B | |
| 1 | × | Potentiometer | |
| 1 | × | ADS1115 ADC Module | |
| 1 | × | Piezo Buzzer | |
| 1 | × | Breadboard | |
| 1 | × | Jumper Wires | |
| 1 | × | (Optional) Screw Terminal Adapter for Raspberry Pi |
Or you can buy the following sensor kits:
| 1 | × | DIYables Sensor Kit (30 sensors/displays) | |
| 1 | × | DIYables Sensor Kit (18 sensors/displays) |
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Overview of Piezo Buzzer and Potentiometer
If you are unfamiliar with piezo buzzer and potentiometer (including pinout, functioning, and programming), the following tutorials can help:
Wiring Diagram
This image is created using Fritzing. Click to enlarge image
Raspberry Pi Code - Simple Sound
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
- Install the Adafruit_ADS1x15 library by running the following commands on your Raspberry Pi terminal:
sudo pip install Adafruit-ADS1x15
- Create a Python script file potentiometer_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-potentiometer-piezo-buzzer
import time
import RPi.GPIO as GPIO
import Adafruit_ADS1x15
# Constants
ADC_CHANNEL = 0 # Analog channel on ADS1015
GAIN = 1 # Gain (1, 2/3, 1, 2, 4, 8, 16)
BUZZER_PIN = 23 # Raspberry Pi GPIO pin connected to the piezo buzzer
# Threshold for triggering the buzzer
THRESHOLD = 700 # Adjust this value based on your requirement
# Setup GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(BUZZER_PIN, GPIO.OUT)
# Create ADS1x15 instance
ads = Adafruit_ADS1x15.ADS1015()
try:
while True:
# Read the raw ADC value from the potentiometer
pot_value = ads.read_adc(ADC_CHANNEL, gain=GAIN)
# Trigger the buzzer if the analog value is greater than the threshold
if pot_value > THRESHOLD:
GPIO.output(BUZZER_PIN, GPIO.HIGH)
else:
GPIO.output(BUZZER_PIN, GPIO.LOW)
print(f"Potentiometer Value: {pot_value}")
time.sleep(0.1)
except KeyboardInterrupt:
GPIO.output(BUZZER_PIN, GPIO.LOW) # Turn off the buzzer before cleanup
GPIO.cleanup()
- Save the file and run the Python script by executing the following command in the terminal:
python3 potentiometer_buzzer.py
- Turn the potentiometer knob.
- Listen to the sound coming from 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
Let play the "Jingle Bells" melody when the potentiometer is turned to a threshold value.
Detailed Instructions
- Create a Python script file potentiometer_buzzer_song.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-potentiometer-piezo-buzzer
import time
import RPi.GPIO as GPIO
import Adafruit_ADS1x15
# Constants
ADC_CHANNEL = 0 # Analog channel on ADS1015
GAIN = 1 # Gain (1, 2/3, 1, 2, 4, 8, 16)
BUZZER_PIN = 23 # Raspberry Pi GPIO pin connected to the piezo buzzer
# Threshold for triggering the buzzer
THRESHOLD = 700 # Adjust this value based on your requirement
# Setup GPIO
GPIO.setmode(GPIO.BCM)
GPIO.setup(BUZZER_PIN, GPIO.OUT)
# Create ADS1x15 instance
ads = Adafruit_ADS1x15.ADS1015()
# 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:
# Read the raw ADC value from the potentiometer
pot_value = ads.read_adc(ADC_CHANNEL, gain=GAIN)
# Trigger the buzzer if the analog value is greater than the threshold
if pot_value > THRESHOLD:
GPIO.output(BUZZER_PIN, GPIO.HIGH)
else:
GPIO.output(BUZZER_PIN, GPIO.LOW)
print(f"Potentiometer Value: {pot_value}")
time.sleep(0.1)
except KeyboardInterrupt:
GPIO.output(BUZZER_PIN, GPIO.LOW) # Turn off the buzzer before cleanup
GPIO.cleanup()
- Save the file and run the Python script by executing the following command in the terminal:
python3 potentiometer_buzzer_song.py
- Turn the potentiometer.
- Hear the song from the piezo buzzer.
Code Explanation
Check out the line-by-line explanation contained in the comments of the source code!