Remarks

MPL3115A2
Status	Not working
Source code	GitHub
NuGet package	Not published

The MPL3115A2 is a barometric pressure sensor capable of reading both temperature and temperature compensated pressure reading. This sensor includes the following features:

• I2C digital interface
• 24-bit ADC
• Altitude and pressure measurements
• Temperature sensor

Sample projects available on GitHub

Purchasing

The MPL3115A2 is available on breakout boards and a weather shield:

• Adafruit MPL3115A2 Breakout Board
• Sparkfun MPL3115A2 Breakout Board
• Sparkfun Weather Shield

Interrupt Mode

The application below connects the MPL3115A2 to two interrupt handlers. These interrupt handlers (events) will display the Temperature and Pressure properties when the handlers are triggered. The sensor is checked every 100 milliseconds (the default for the updatePeriod).

public class MeadowApp : App<F7Micro, MeadowApp>
{
    public MeadowApp()
    {
        Console.WriteLine("MPL3115A2 Interrupt Example");
        var mpl3115a2 = new MPL3115A2(temperatureChangeNotificationThreshold: 0.1F);
        mpl3115a2.TemperatureChanged += (s, e) =>
        {
            Console.WriteLine("Temperature: " + mpl3115a2.Temperature.ToString("f2"));
        };
        mpl3115a2.PressureChanged += (s, e) =>
        {
            Console.WriteLine("Pressure: " + mpl3115a2.Pressure.ToString("f2")); 
        };
        Thread.Sleep(Timeout.Infinite);
    }
}

Polling Mode

The following application reads the temperature and pressure every second and displays the result on the debug console:

public class MeadowApp : App<F7Micro, MeadowApp>
{
    public MeadowApp()
    {
        Console.WriteLine("MPL3115A2 Polling Example");
        var mpl3115a2 = new MPL3115A2(updateInterval: 0);
        while (true)
        {
            mpl3115a2.Update();
            Console.WriteLine("Temperature: " + mpl3115a2.Temperature.ToString("f2") + ", Pressure: " + mpl3115a2.Pressure.ToString("f2"));
            Thread.Sleep(1000);
        }
    }
}

Wiring Example

MPL3115A2 configured for polling more data reads:

Characteristic	Locus
Inheritance	System.Object > Mpl3115a2
Implements	IAtmosphericSensor
Namespace	Meadow.Foundation.Sensors.Atmospheric
Assembly	MPL3115A2.dll

Syntax

public class Mpl3115a2 : FilterableChangeObservableBase<AtmosphericConditionChangeResult, AtmosphericConditions>, IAtmosphericSensor

Constructors

Mpl3115a2(II2cBus, Byte)

Create a new MPL3115A2 object with the default address and speed settings.

Declaration

public Mpl3115a2(II2cBus i2cBus, byte address = 96)

Parameters

Type	Name	Description
II2cBus	i2cBus	I2cBus (Maximum is 400 kHz).
System.Byte	address	Address of the sensor (default = 0x60).

Properties

Conditions

The AtmosphericConditions from the last reading.

Declaration

public AtmosphericConditions Conditions { get; protected set; }

Property Value

Type	Description
AtmosphericConditions

IsSampling

Gets a value indicating whether the analog input port is currently sampling the ADC. Call StartSampling() to spin up the sampling process.

Declaration

public bool IsSampling { get; protected set; }

Property Value

Type	Description
System.Boolean	true if sampling; otherwise, false.

Pressure

The pressure, in hectopascals (hPa), from the last reading. 1 hPa is equal to one millibar, or 1/10th of a kilopascal (kPa)/centibar.

Declaration

public float Pressure { get; }

Property Value

Type	Description
System.Single

Standby

Check if the part is in standby mode or change the standby mode.

Declaration

public bool Standby { get; set; }

Property Value

Type	Description
System.Boolean

Remarks

Changes the SBYB bit in Control register 1 to put the device to sleep or to allow measurements to be made.

Status

Get the status register from the sensor.

Declaration

public byte Status { get; }

Property Value

Type	Description
System.Byte

Temperature

The temperature, in degrees celsius (°C), from the last reading.

Declaration

public float Temperature { get; }

Property Value

Type	Description
System.Single

Methods

RaiseChangedAndNotify(AtmosphericConditionChangeResult)

Declaration

protected void RaiseChangedAndNotify(AtmosphericConditionChangeResult changeResult)

Parameters

Type	Name	Description
AtmosphericConditionChangeResult	changeResult

Read()

Convenience method to get the current sensor readings. For frequent reads, use StartSampling() and StopSampling() in conjunction with the SampleBuffer.

Declaration

public Task<AtmosphericConditions> Read()

Returns

Type	Description
System.Threading.Tasks.Task<AtmosphericConditions>

ReadSensor()

Declaration

protected Task<AtmosphericConditions> ReadSensor()

Returns

Type	Description
System.Threading.Tasks.Task<AtmosphericConditions>

Reset()

Reset the sensor.

Declaration

public void Reset()

StartUpdating(Int32)

Declaration

public void StartUpdating(int standbyDuration = 1000)

Parameters

Type	Name	Description
System.Int32	standbyDuration

StopUpdating()

Stops sampling the temperature.

Declaration

public void StopUpdating()

Events

Updated

Declaration

public event EventHandler<AtmosphericConditionChangeResult> Updated

Event Type

Type	Description
System.EventHandler<AtmosphericConditionChangeResult>