Remarks

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

                <img src="https://img.shields.io/nuget/v/Meadow.Foundation.Sensors.Hid.Mpr121.svg?label=Meadow.Foundation.Sensors.Hid.Mpr121" 
                style="width: auto; height: -webkit-fill-available;" /></a> |

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:

Characteristic	Locus
Inheritance	System.Object > Mpr121
Namespace	Meadow.Foundation.Sensors.Hid
Assembly	Mpr121.dll

Syntax

public class Mpr121 : object

Constructors

Mpr121(II2cBus, Byte, Int32, Mpr121.Mpr121Configuration)

Create a new MPR121 keypad object.

Declaration

public Mpr121(II2cBus i2cBus, byte address = null, int refreshPeriod = null, Mpr121.Mpr121Configuration configuration = null)

Parameters

Type	Name	Description
II2cBus	i2cBus
System.Byte	address
System.Int32	refreshPeriod
Mpr121.Mpr121Configuration	configuration

Properties

RefreshPeriod

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

Declaration

public int RefreshPeriod { get; set; }

Property Value

Type	Description
System.Int32

Methods

ReadChannelStatus(Mpr121.Channels)

Reads the channel status of MPR121 controller.

Declaration

public bool ReadChannelStatus(Mpr121.Channels channel)

Parameters

Type	Name	Description
Mpr121.Channels	channel	The channel to read status.

Returns

Type	Description
System.Boolean

ReadChannelStatuses()

Reads the channel statuses of MPR121 controller.

Declaration

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

Returns

Type	Description
IReadOnlyDictionary<Mpr121.Channels, System.Boolean>

Events

ChannelStatusesChanged

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

Declaration

public event EventHandler<ChannelStatusChangedEventArgs> ChannelStatusesChanged

Event Type

Type	Description
EventHandler<ChannelStatusChangedEventArgs>