Meadow.Foundation.Sensors.LoadCell.Nau7802 1.3.0

Meadow.Foundation.Sensors.LoadCell.Nau7802

NAU7802 I2C 24-Bit dual channel analog to digital converter

The Nau7802 library is designed for the Wilderness Labs Meadow .NET IoT platform and is part of Meadow.Foundation

The Meadow.Foundation peripherals library is an open-source repository of drivers and libraries that streamline and simplify adding hardware to your C# .NET Meadow IoT application.

For more information on developing for Meadow, visit developer.wildernesslabs.co, to view all of Wilderness Labs open-source projects, including samples, visit github.com/wildernesslabs

Usage

private Nau7802 loadSensor;

public int CalibrationFactor { get; set; } = 16526649; // TODO: change this based on your scale (using the method provided below)
public Mass CalibrationWeight { get; set; } = new Mass(1600, Mass.UnitType.Grams); // TODO: enter the known-weight you used in calibration

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

    loadSensor = new Nau7802(Device.CreateI2cBus());

    if (CalibrationFactor == 0)
    {
        await GetAndDisplayCalibrationUnits(loadSensor);
    }
    else
    {   // wait for the ADC to settle
        await Task.Delay(500);

        // Set the current load to be zero
        loadSensor.SetCalibrationFactor(CalibrationFactor, CalibrationWeight);
        loadSensor.Tare();
    }

    loadSensor.MassUpdated += (sender, values) => Resolver.Log.Info($"Mass is now returned {values.New.Grams:N2}g");
}

public override Task Run()
{
    loadSensor.StartUpdating(TimeSpan.FromSeconds(2));

    return Task.CompletedTask;
}

public async Task GetAndDisplayCalibrationUnits(Nau7802 sensor)
{
    // first notify the user we're starting
    Resolver.Log.Info($"Beginning Calibration. First we'll tare (set a zero).");
    Resolver.Log.Info($"Make sure scale bed is clear. Next step in 5 seconds...");

    await Task.Delay(5000);
    sensor.Tare();
    Resolver.Log.Info($"Place a known weight on the scale. Next step in 5 seconds...");

    await Task.Delay(500);
    var factor = sensor.CalculateCalibrationFactor();

    Resolver.Log.Info($"Your scale's Calibration Factor is: {factor}. Enter this into the code for future use.");
}