Using a High Temperature Sensor with an MSP430 evaluation module…Using a 12 bit A/D with a 2.5V reference…I am trying to take the library function and implement it but am not sure about a few things. In particular TI has a paper that specifically says it is an error to add NTC temperature to Thermocouple temperature to get final temp per your code. The correct method is to add NTC mV to Thermocouple mV and THEN use the polynomial lookup…TI Whitepaper SBAA274 refer to section 1.4.4.
So with this said I am trying to understand the NTC section of your code. In particular I would like to get the voltage of the NTC NOT the resistance…Please correct me if I am wrong but I believe to do this would be
4096/2.5V = A/D cnts / Vin
and then if I take
Vin - 1.5V (this is a 10k NTC in series with the 10k resistor and 3.3V across the two) I will get the voltage to add to the thermocouple to THEN go to the tables and lookup?
Sincerely
Steve