mzwaterski

Those are available in the Math library. Math.Pow(), Math.Log()

-dan

Thanks for your response. I tried this, and the Pow() function now works, but the Log() function is not working (e.g., System.Math.Log(ThermResistance / ThermRefResistance) reports that System.Math does not contain a definition for 'Log'). Do I need to somehow get a different Math library or version of something?

Thanks in advance for any help that you can provide.

Mike

Below is how I applied it in C. If you have any questions, let me know!

//ADC_Value Accepted, Farenheit Returned
	double GetFarenheit(int ADC_Value)
	{
		//Define reference voltage
		double Vref = 5;

		//Define thremistor value
		double ThermRefResistance = 10000;
	
		//Convert ADC reading to a voltage
		double Vin = (Vref * ADC_Value) / 1024;
	
		//Convert Voltage to resistance
		double ThermResistance = ThermRefResistance/((Vref/Vin)-1);

		// Steinhart constants for thermistor (Vishay NTCLE203E3103FB0)
		double a = 3.354016 * pow(10, -3);
		double b = 2.56985 * pow(10, -4);
		double c = 2.620131 * pow(10, -6);
		double d = 6.383091 * pow(10, -8);

		//Convert resistance to temperature in degrees C (Steinhart equation)
		double Celcius = 1/(a + b * log(ThermResistance/ThermRefResistance) + c * pow(log(ThermResistance/ThermRefResistance), 2) + d * pow(log(ThermResistance/ThermRefResistance), 3)) - 272.15;
		
		//Convert celcius to farenheit

		return Farenheit = 18 * Celcius + 320;

	}

Is it possible to use this code with the Netduino? When I try and use this, I'm told that the pow() and log() functions do not exist. Is there a package that I need to add to my environment?