Hi all,
Could you please help me work out what resistor I should use when connecting a 100k thermistor to my Arduino.
My Thermistor is:
EPCOS 100K Thermistor (B57540G0104F000)
I found the following tutorial but they are using a 10k thermistor (instead of 100k).
http://bildr.org/2012/11/thermistor-arduino/
Does this mean that I should use a 100k resistor instead of 10k?
Thanks!
Use a 100K resistor
Print your thermistor datasheet. And go to the link above. Your goal us to determine an appropriate series resistor that will never allow too much current to induce self-heating while at the SAME time provide you with a voltage drop (swing) that ranges (maps) within the Arduino's 10-bit AD such that you achieve the desired AD resolution. You cannot just do this with a 100K since I do not know your high/low measuring points that your intended use. Playing with a Rs of 100K is OK (2.5V approx.) to the Arduino AD pin when the value of the NTC thermistor is 100K.
Nice sketch here: Using a Thermistor | Thermistor | Adafruit Learning System
Nice schematic here: Temperature Sensor v1.1 - RepRap, with 10uF capacitor I get really stable readings