Meadow.Foundation.Sensors.Hid.Mpr121

Mpr121
Status
Source code	GitHub
Datasheet(s)	GitHub
NuGet package

Code Example

public override Task Initialize()
{
    Resolver.Log.Info("Initialize...");

    var sensor = new Mpr121(Device.CreateI2cBus(Meadow.Hardware.I2cBusSpeed.Standard), 90, 100);
    sensor.ChannelStatusesChanged += Sensor_ChannelStatusesChanged;

    return Task.CompletedTask;
}

private void Sensor_ChannelStatusesChanged(object sender, ChannelStatusChangedEventArgs e)
{
    string pads = string.Empty;

    for (int i = 0; i < e.ChannelStatus.Count; i++)
    {
        if (e.ChannelStatus[(Mpr121.Channels)i] == true)
        {
            pads += i + ", ";
        }
    }

    var msg = string.IsNullOrEmpty(pads) ? "none" : (pads + "touched");
    Resolver.Log.Info(msg);
}

Sample project(s) available on GitHub

Wiring Example

To wire a Mpr121 to your Meadow board, connect the following:

Mpr121	Meadow Pin
GND	GND
SCL	D08 (SCL)
SDA	D07 (SDA)
VCC	3V3

It should look like the following diagram:

Class Mpr121

Represents the MPR121 12-Key Capacitive Touch Sensor

Assembly: Mpr121.dll

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Declaration

public class Mpr121 : II2cPeripheral

Implements:
Meadow.Hardware.II2cPeripheral

Properties

DefaultI2cAddress

The default I2C address for the peripheral

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Declaration

public byte DefaultI2cAddress { get; }

RefreshPeriod

Gets or sets the period in milliseconds to refresh the channels statuses.

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Declaration

public int RefreshPeriod { get; set; }

Fields

i2cComms

I2C Communication bus used to communicate with the peripheral

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Declaration

protected readonly II2cCommunications i2cComms

Methods

ReadChannelStatus(Channels)

Reads the channel status of MPR121 controller.

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Declaration

public bool ReadChannelStatus(Mpr121.Channels channel)

Returns

System.Boolean

Parameters

Type	Name	Description
Meadow.Foundation.Sensors.Hid.Mpr121.Channels	channel	The channel to read status.

ReadChannelStatuses()

Reads the channel statuses of MPR121 controller.

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Declaration

public IReadOnlyDictionary<Mpr121.Channels, bool> ReadChannelStatuses()

Returns

System.Collections.Generic.IReadOnlyDictionary<Meadow.Foundation.Sensors.Hid.Mpr121.Channels,System.Boolean>

Events

ChannelStatusesChanged

Notifies about a the channel statuses have been changed. Refresh period can be changed by setting PeriodRefresh property.

View Source

Declaration

public event EventHandler<ChannelStatusChangedEventArgs> ChannelStatusesChanged

Event Type

System.EventHandler<Meadow.Foundation.Sensors.Hid.ChannelStatusChangedEventArgs>

Implements

• Meadow.Hardware.II2cPeripheral