I'm going to be using a couple of thermistors to do wide range (32F - 350F) temperature readings. The thermistor is going to be in a voltage gate so i can get analog voltage readings from it. The problem with a thermistor is that its resistance in relation to temperature does not change in a linear fashion. Rather, it is a curve that is defined by a complicated formula (Steinhart Hart equation). Unfortunately this equation makes use "ln()", which is something that is very difficult/slow to implement on the arduino.
So I have two options... 1) Make a lookup table with these values. 2) Fit exponential curves to portions of the curve. Select the curve based on the inputs.
Currently I'm leaning towards #1. I would have a 2x318 array that would contain these values. That would take up approx 2 * 2 * 318 = 1272 bytes. That's not very good. Plus I haven't really figured out how i'm going to search for them. A loop with if-then's doesn't sounds very fast.