Remarks

PiezoSpeaker
Status
Source code	GitHub
NuGet package

The PiezoSpeaker class represents a piezoelectric speaker that can be used to generate tones across a range of frequencies. They typically perform well between 1-5kHz but may go as high as 100kHz. PiezoSpeaker Implements IToneGenerator.

The positive pin of the piezo speaker connects to a pulse width modulation (PWM) capable pin on the Meadow and the negative pin connects to common/ground. A resistor can be placed in-line to reduce volume.

Code Example

The following example shows how to initialize a PiezoSpeaker and play an A4 note for one second:

public class MeadowApp : App<F7Micro, MeadowApp>
{        
    protected PiezoSpeaker piezoSpeaker;

    public MeadowApp()
    {
        Console.WriteLine("Initializing...");

        piezoSpeaker = new PiezoSpeaker(Device.CreatePwmPort(Device.Pins.D10));

        TestPiezoSpeaker();
    }

    protected void TestPiezoSpeaker()
    {
        Console.WriteLine("TestPiezoSpeaker...");

        while (true)
        {
            Console.WriteLine("Playing A4 note!");
            piezoSpeaker.PlayTone(440, 1000);
            piezoSpeaker.StopTone();
            Thread.Sleep(500);
        }
    }
}

Sample projects available on GitHub

Wiring Example

Characteristic	Locus
Inheritance	System.Object > PiezoSpeaker
Namespace	Meadow.Foundation.Audio
Assembly	Meadow.Foundation.dll

Syntax

public class PiezoSpeaker : IToneGenerator

Constructors

PiezoSpeaker(IIODevice, IPin, Single, Single)

Create a new PiezoSpeaker instance

Declaration

public PiezoSpeaker(IIODevice device, IPin pin, float frequency = 100F, float dutyCycle = 0F)

Parameters

Type	Name	Description
IIODevice	device
IPin	pin	PWM Pin connected to the PiezoSpeaker
System.Single	frequency
System.Single	dutyCycle

PiezoSpeaker(IPwmPort)

Create a new PiezoSpeaker instance

Declaration

public PiezoSpeaker(IPwmPort port)

Parameters

Type	Name	Description
IPwmPort	port

Properties

Port

Gets the port that is driving the Piezo Speaker

Declaration

public IPwmPort Port { get; protected set; }

Property Value

Type	Description
IPwmPort

Methods

PlayTone(Single, Int32)

Play a frequency for a specified duration

Declaration

public void PlayTone(float frequency, int duration = 0)

Parameters

Type	Name	Description
System.Single	frequency	The frequency in hertz of the tone to be played
System.Int32	duration	How long the note is played in milliseconds, if durration is 0, tone plays indefinitely

StopTone()

Stops a tone playing

Declaration

public void StopTone()