How to Use Piezo Speaker: Examples, Pinouts, and Specs

A piezo speaker is a type of loudspeaker that uses the piezoelectric effect to produce sound. It converts electrical energy into mechanical energy, creating sound waves through the vibration of a diaphragm. Piezo speakers are compact, lightweight, and energy-efficient, making them ideal for a wide range of applications.

• Alarm systems and buzzers
• Keypad feedback in electronic devices
• Toys and small gadgets
• Notification sounds in appliances
• Audio signaling in embedded systems

Below are the general technical specifications for a typical piezo speaker. Note that specific values may vary depending on the model.

Piezo speakers typically have two pins:

1. Basic Connection: Connect the positive pin of the piezo speaker to the output signal (e.g., a microcontroller pin or an oscillator circuit). Connect the negative pin to the ground (GND).
2. Driving the Speaker: Use a square wave signal to drive the piezo speaker. The frequency of the square wave determines the pitch of the sound produced.
3. Resistor in Series: To limit current and protect the speaker, you may add a resistor (e.g., 1 kΩ) in series with the positive pin.

Below is an example of how to connect and use a piezo speaker with an Arduino UNO to generate a tone.

• Connect the positive pin of the piezo speaker to Arduino pin 8.
• Connect the negative pin of the piezo speaker to the GND pin of the Arduino.

// Piezo Speaker Example with Arduino UNO
// Generates a tone on pin 8 of the Arduino

const int piezoPin = 8; // Pin connected to the piezo speaker

void setup() {
  // No setup required for this example
}

void loop() {
  tone(piezoPin, 1000); // Generate a 1 kHz tone
  delay(500);           // Play the tone for 500 ms
  noTone(piezoPin);     // Stop the tone
  delay(500);           // Wait for 500 ms before repeating
}

• Frequency Range: Ensure the driving frequency matches the resonant frequency of the piezo speaker for optimal sound output.
• Voltage Limits: Do not exceed the maximum operating voltage to avoid damaging the speaker.
• Mounting: Secure the piezo speaker properly to prevent unwanted vibrations or noise.

1. No Sound Output:

   • Check the connections to ensure the positive and negative pins are correctly wired.
   • Verify that the driving signal is within the operating voltage and frequency range.

2. Distorted Sound:

   • Ensure the driving frequency matches the resonant frequency of the piezo speaker.
   • Check for loose connections or improper mounting.

3. Low Volume:

   • Increase the driving voltage, but ensure it does not exceed the maximum rating.
   • Use a proper driving circuit to amplify the signal if needed.

Q: Can I use a piezo speaker without a microcontroller?
A: Yes, you can use a simple oscillator circuit (e.g., a 555 timer) to drive the piezo speaker.

Q: What is the difference between a piezo speaker and a piezo buzzer?
A: A piezo speaker requires an external driving signal (e.g., a square wave), while a piezo buzzer has a built-in oscillator and only needs a DC voltage to operate.

Q: Can I use PWM to control the piezo speaker?
A: Yes, PWM (Pulse Width Modulation) can be used to generate tones by varying the frequency of the signal.

This concludes the documentation for the piezo speaker.