100prznt / Rca.Sht85Lib

Open source UWP library for communication with Sensirion Humidity Sensor SHT85.

SHT85 Library

Open source UWP library for communication with Sensirion Humidity Sensor SHT85.

This library targets UWP IoT projects! Download directly from NuGet Rca.Sht85Lib on NuGet.

Hardware functionality

• SingleShot support (temperature and rel. humidity)
• Periodic data acquisition support incl. timestamp
• Control sensor heater
• Read serial and status-register

Software features

• Physics calculator for:
  • Dew point
  • Absolute humidity
  • Vapour-pressure
  • Saturation-vapour-pressure

How To install?

Download the source from GitHub or get the compiled assembly from NuGet Rca.Sht85Lib on NuGet.

How to use?

All measured and calculated values are of the data type double and are given in the following units:

Value	Unit	Range
Temperature	°C
Relative humidity	%RH	0..100
Absolute humidity	%	0..100
Dew point	°C
Vapour pressure	hPa
Saturation vapour pressure	hPa

In the following a few basic usage examples of the library.

Create an sensor instance

In this example is the I2C address of conneted SHT85 sensor set to default (0x44 factory-fixed):

var mySht85Sensor = new Rca.Sht85Lib.Sht85();

Perform and read measurement

Perform a single reading with default repeatability "low":

var measData = mySht85Sensor.SingleShot(); //Tuple<double, double>
var temperature = measData.Item1;          //double
var humidity = measData.Item2;             //double

Periodic Data Acquisition Mode

Start the periodic data acquisition mode with specified measure mode:

void StartPeriodicDataAcquisitionMode()
{
	//...
	mySht85Sensor.NewMeasData += mySht85Sensor_NewMeasData;
	mySht85Sensor.StartPeriodicDataAcquisitionMode(PeriodicMeasureModes.High10Hz);
	//...
}

Method to receive the NewMeasData event. The update rate depends on the selected measure mode and the hardware runtimes:

void mySht85Sensor_NewMeasData(Tuple<DateTime, double, double> measData)
{
	var timeStamp = measData.Item1;   //DateTime object
	var temperature = measData.Item2; //double
	var humidity = measData.Item3;    //double
}

Use the Physics.Calculator

The library also offers a calculator, which offers the possibility to calculate further sizes. measData is an Tuple<double, double> object (Item1: temperature in °C; Item2: rel. humidity in %RH), e.g. provided by SigleShot().

var myCalculator = new Rca.Sht85Lib.Physics.Calculator();

var dewPoint = myCalculator.DewPoint(measData);            //double
var absHumidity = myCalculator.AbsoluteHumidity(measData); //double

Credits

This library is made possible by contributions from:

• Elias Rümmler (@rmmlr) - core contributor

License

Rca.Sht85Lib is licensed under MIT. Refer to LICENSE.txt for more information.

Contributions

Contributions are welcome. Fork this repository and send a pull request if you have something useful to add.

Related Projects

• Rca.EzoDeviceLib - Another sensor library for water analytics with Atlas Scientific EZO modules.