Thermistor Vs. LM335A?

I am trying to use the arduino to do some temperature sensing and am trying to decide if a thermistor or a LM335A analog temperature sensor is better. I originally wanted to use whatever came out of an old digital thermometer but it was a thermistor with no markings and obtaining the coefficients for the Steinhart-hart formula doesn't seem likely. the Programming seems like it would be easier with the LM335A but i haven't worked with either. also the Thermistor is about 45 cents more.


Paul and I built an Arduino digital temperature sensor that plugs right into the analog pins, and it can get up and running to read temperatures over serial pretty quickly.

It might help you get around messing with thermistors and playing with the Steinhart-Hart formula :)

Hope this helps, Justin

Neither, use DS1820s. Thermisitors are a nighmare to get to read something that represents reality. The LM 335s are sensitive to the AREF voltage. The Aref varies with the supply voltage, It will usually be pretty close to 5V using external power through the regulator, but it could be 5% or more out on USB power and your reading are miles out.

You can hook quite a few DS1820s up to one digital pin. Nice ready made librarys, can’t beat 'em in my opinion…