public void TestConvertVoltageToResistance2()
{
// Got Resistance 235409.820661915 from voltage 2.3161289870739
double data = TempUtils.GetThermistorResistenceFromVoltage(3.3, 2.3161289870739, 100000);
Assert.AreEqual(42479, (int)data);
}
public void TestConvertVoltageToResistence()
{
// This was checked with https://www.allaboutcircuits.com/tools/voltage-divider-calculator/
double data = TempUtils.GetThermistorResistenceFromVoltage(3.3, 1.66, 100000);
Assert.AreEqual(98795, (int)data);
}
public async Task <Temps> ReadThermometer(int index)
{
if (index < 0 || index > 7)
{
throw new IndexOutOfRangeException("Index must be from 0-7");
}
using (await this.thermometerLock.LockAsync())
{
await this.initTask;
double sum = 0;
const int numSamples = 3;
for (int i = 0; i < numSamples; i++)
{
var reading = this.mcp.Read(Channels[index]);
sum += reading.NormalizedValue;
await Task.Delay(100);
}
double averageValue = sum / numSamples;
//Debug.WriteLine($"Reading for thermometer {index} is {reading.RawValue}, Normalized: {reading.NormalizedValue}");
double voltage = averageValue * InputVoltage;
double resistance = TempUtils.GetThermistorResistenceFromVoltage(3.3, voltage, BalancingResistorOhms);
//Debug.WriteLine($"Got Resistance {resistance} from voltage {voltage}");
CoefficientSet coefficients = Coefficients[0];
var temps = new Temps();
if (double.IsInfinity(resistance))
{
temps.Kelvin = 0;
}
else
{
temps.Kelvin = TempUtils.ResistanceToTemp(coefficients.A, coefficients.B, coefficients.C, resistance);
}
temps.Celcius = TempUtils.KelvinToCelcius(temps.Kelvin);
temps.Farenheight = TempUtils.CelciusToFarenheight(temps.Celcius);
return(temps);
}
}
