/// <summary>
/// Read temperature compensated relative humidity
/// </summary>
/// <param name="VDD">VDD for SHT11</param>
/// <returns>Relative Humidity in percent</returns>
public double ReadRelativeHumidity(SHT11VDD_Voltages VDD)
{
double c1;
double c2;
double c3;
double t1;
double t2;
// Check if we have 8 or 12 bits humidity
if (((byte)ReadStatusRegister() & 0x01) == 0x01)
{
// 8 bit
c1 = -2.0468F;
c2 = 0.5872F;
c3 = -4.0845E-4F;
t1 = 0.01F;
t2 = 0.00128F;
}
else
{
// 12 bit
c1 = -2.0468F;
c2 = 0.0367F;
c3 = -1.5955E-6F;
t1 = 0.01F;
t2 = 0.00008F;
}
// Read Humidity from SHT11
double SOrh = ReadHumidityRaw();
// Calculate relative humidity
double RHlinear = c1 + (c2 * SOrh) + (c3 * (SOrh * SOrh));
// Read Temperature for temperature compensation
double Tc = ReadTemperature(VDD, SHT11TemperatureUnits.Celcius);
// Calculate temperature compensated humidity
double RHtrue = ((Tc - 25.0F) * (t1 + (t2 * SOrh))) + RHlinear;
// Return Relative Humidity
return(RHtrue);
}
/// <summary>
/// Read Temperature
/// </summary>
/// <param name="VDD">VDD Voltage for SHT11</param>
/// <param name="TemperatureUnit">Temperature units to return</param>
/// <returns>Temperature in TemperatureUnit units</returns>
public double ReadTemperature(SHT11VDD_Voltages VDD, SHT11TemperatureUnits TemperatureUnit)
{
double readTemp = 0.0F;
double multplier = 0.0F;
if (TemperatureUnit == SHT11TemperatureUnits.Celcius)
{
switch (VDD)
{
case SHT11VDD_Voltages.VDD_2_5V:
readTemp = -39.4F;
break;
case SHT11VDD_Voltages.VDD_3_5V:
readTemp = -39.7F;
break;
case SHT11VDD_Voltages.VDD_3V:
readTemp = -39.6F;
break;
case SHT11VDD_Voltages.VDD_4V:
readTemp = -39.8F;
break;
case SHT11VDD_Voltages.VDD_5V:
readTemp = -40.1F;
break;
}
}
if (TemperatureUnit == SHT11TemperatureUnits.Farenheid)
{
switch (VDD)
{
case SHT11VDD_Voltages.VDD_2_5V:
readTemp = -38.9F;
break;
case SHT11VDD_Voltages.VDD_3_5V:
readTemp = -39.5F;
break;
case SHT11VDD_Voltages.VDD_3V:
readTemp = -39.3F;
break;
case SHT11VDD_Voltages.VDD_4V:
readTemp = -39.6F;
break;
case SHT11VDD_Voltages.VDD_5V:
readTemp = -40.2F;
break;
}
}
// Check if we have 12 or 14 bits temperature
if (((byte)ReadStatusRegister() & 0x01) == 0x01)
{
// 12 Bit
switch (TemperatureUnit)
{
case SHT11TemperatureUnits.Farenheid:
multplier = 0.072F;
break;
case SHT11TemperatureUnits.Celcius:
multplier = 0.04F;
break;
}
}
else
{
// 14 Bit
switch (TemperatureUnit)
{
case SHT11TemperatureUnits.Farenheid:
multplier = 0.018F;
break;
case SHT11TemperatureUnits.Celcius:
multplier = 0.01F;
break;
}
}
// Calculate actual temperature
readTemp += (double)ReadTemperatureRaw() * multplier;
// Return temperature
return readTemp;
}
/// <summary>
/// Read temperature compensated relative humidity
/// </summary>
/// <param name="VDD">VDD for SHT11</param>
/// <returns>Relative Humidity in percent</returns>
public double ReadRelativeHumidity(SHT11VDD_Voltages VDD)
{
double c1;
double c2;
double c3;
double t1;
double t2;
// Check if we have 8 or 12 bits humidity
if (((byte)ReadStatusRegister() & 0x01) == 0x01)
{
// 8 bit
c1 = -2.0468F;
c2 = 0.5872F;
c3 = -4.0845E-4F;
t1 = 0.01F;
t2 = 0.00128F;
}
else
{
// 12 bit
c1 = -2.0468F;
c2 = 0.0367F;
c3 = -1.5955E-6F;
t1 = 0.01F;
t2 = 0.00008F;
}
// Read Humidity from SHT11
double SOrh = ReadHumidityRaw();
// Calculate relative humidity
double RHlinear = c1 + (c2 * SOrh) + (c3 * (SOrh * SOrh));
// Read Temperature for temperature compensation
double Tc = ReadTemperature(VDD, SHT11TemperatureUnits.Celcius);
// Calculate temperature compensated humidity
double RHtrue = ((Tc - 25.0F) * (t1 + (t2 * SOrh))) + RHlinear;
// Return Relative Humidity
return RHtrue;
}
/// <summary>
/// Read Temperature
/// </summary>
/// <param name="VDD">VDD Voltage for SHT11</param>
/// <param name="TemperatureUnit">Temperature units to return</param>
/// <returns>Temperature in TemperatureUnit units</returns>
public double ReadTemperature(SHT11VDD_Voltages VDD, SHT11TemperatureUnits TemperatureUnit)
{
double readTemp = 0.0F;
double multplier = 0.0F;
if (TemperatureUnit == SHT11TemperatureUnits.Celcius)
{
switch (VDD)
{
case SHT11VDD_Voltages.VDD_2_5V:
readTemp = -39.4F;
break;
case SHT11VDD_Voltages.VDD_3_5V:
readTemp = -39.7F;
break;
case SHT11VDD_Voltages.VDD_3V:
readTemp = -39.6F;
break;
case SHT11VDD_Voltages.VDD_4V:
readTemp = -39.8F;
break;
case SHT11VDD_Voltages.VDD_5V:
readTemp = -40.1F;
break;
}
}
if (TemperatureUnit == SHT11TemperatureUnits.Farenheid)
{
switch (VDD)
{
case SHT11VDD_Voltages.VDD_2_5V:
readTemp = -38.9F;
break;
case SHT11VDD_Voltages.VDD_3_5V:
readTemp = -39.5F;
break;
case SHT11VDD_Voltages.VDD_3V:
readTemp = -39.3F;
break;
case SHT11VDD_Voltages.VDD_4V:
readTemp = -39.6F;
break;
case SHT11VDD_Voltages.VDD_5V:
readTemp = -40.2F;
break;
}
}
// Check if we have 12 or 14 bits temperature
if (((byte)ReadStatusRegister() & 0x01) == 0x01)
{
// 12 Bit
switch (TemperatureUnit)
{
case SHT11TemperatureUnits.Farenheid:
multplier = 0.072F;
break;
case SHT11TemperatureUnits.Celcius:
multplier = 0.04F;
break;
}
}
else
{
// 14 Bit
switch (TemperatureUnit)
{
case SHT11TemperatureUnits.Farenheid:
multplier = 0.018F;
break;
case SHT11TemperatureUnits.Celcius:
multplier = 0.01F;
break;
}
}
// Calculate actual temperature
readTemp += (double)ReadTemperatureRaw() * multplier;
// Return temperature
return(readTemp);
}
