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);
}
}
public void TestTheseNumbers()
{
double a, b, c;
a = -1.373357407E-3;
b = 4.914938378E-4;
c = -5.890760444E-7;
double tempK = TempUtils.ResistanceToTemp(a, b, c, 101219);
Assert.AreEqual(295, Math.Round(tempK));
double tempC = TempUtils.KelvinToCelcius(tempK);
Assert.AreEqual(22, Math.Round(tempC));
double tempF = TempUtils.CelciusToFarenheight(tempC);
Assert.AreEqual(71, Math.Round(tempF));
}
public void TestAgain()
{
// 33500 / 122F
double a, b, c;
a = -1.373357407E-3;
b = 4.914938378E-4;
c = -5.890760444E-7;
double tempK = TempUtils.ResistanceToTemp(a, b, c, 33500);
Assert.AreEqual(325, Math.Round(tempK));
double tempC = TempUtils.KelvinToCelcius(tempK);
Assert.AreEqual(51, Math.Round(tempC));
double tempF = TempUtils.CelciusToFarenheight(tempC);
Assert.AreEqual(124, Math.Round(tempF));
}