/// <summary>
/// Uses the temperature lookup table to convert a resistance into
/// a thermistor temperature
/// </summary>
/// <param name="r">The measured resistance</param>
/// <param name="type">The type of thermistor</param>
/// <returns>The temperature of the thermistor</returns>
public static double ConvertRToT(double r, ThermistorType type)
{
switch (type)
{
case (ThermistorType.Warner):
if (r < R0_Warner)
{
r = R0_Warner;
}
if (r > RMax_Warner)
{
r = RMax_Warner;
}
return(T_Warner[(int)r - R0_Warner]);
default:
if (r < R0_Omega)
{
r = R0_Omega;
}
if (r > RMax_Omega)
{
r = RMax_Omega;
}
return(T_Omega[(int)r - R0_Omega]);
}
}
/// <summary>
/// Constructs a new thermistor
/// </summary>
/// <param name="daq">The daq-board for reading the thermistor</param>
/// <param name="channelName">The ai channel readint the thermistor bridge</param>
/// <param name="type">The type of the thermistor</param>
public Thermistor(PCIe6323 daq, string channelName, ThermistorType type)
{
if (ViewModelBase.IsInDesignMode)
{
Temperature = 12.3456789;
return;
}
_type = type;
if (channelName.ToLower() == "ai0")
{
daq.AI.AI0.MinValue = -5;
daq.AI.AI0.MaxValue = 5;
daq.AI.AI0.Callback = (sampleIndex, samples) => {
int length = samples.Length;
double sum = 0;
for (int i = 0; i < length; i++)
{
sum += samples[i];
}
Temperature = ConvertRToT(ConvertVToR(sum / length), _type);
};
}
if (channelName.ToLower() == "ai1")
{
daq.AI.AI1.MinValue = -5;
daq.AI.AI1.MaxValue = 5;
daq.AI.AI1.Callback = (sampleIndex, samples) => {
int length = samples.Length;
double sum = 0;
for (int i = 0; i < length; i++)
{
sum += samples[i];
}
Temperature = ConvertRToT(ConvertVToR(sum / length), _type);
};
}
if (channelName.ToLower() == "ai2")
{
daq.AI.AI2.MinValue = -5;
daq.AI.AI2.MaxValue = 5;
daq.AI.AI2.Callback = (sampleIndex, samples) => {
int length = samples.Length;
double sum = 0;
for (int i = 0; i < length; i++)
{
sum += samples[i];
}
Temperature = ConvertRToT(ConvertVToR(sum / length), _type);
};
}
if (channelName.ToLower() == "ai3")
{
daq.AI.AI3.MinValue = -5;
daq.AI.AI3.MaxValue = 5;
daq.AI.AI3.Callback = (sampleIndex, samples) => {
int length = samples.Length;
double sum = 0;
for (int i = 0; i < length; i++)
{
sum += samples[i];
}
Temperature = ConvertRToT(ConvertVToR(sum / length), _type);
};
}
}
