NTC Thermisitor

Projects General Guidance
1

Hi all
I would like to build a temperature sensor that logs the temperature every 15 mins overnight.
I have two main questions regarding this project:

  1. How to convert the reading from the analog pin to one in degrees Celsius. I currently have the thermistor set up in a voltage divider with a 10K. I have searched this on google and on the forum but nothing's worked so far.
  2. How to store the values. I have a mega, so I could store the values in EEPROM, as that would have space for 4096 bytes, unless anyone has any better ideas.
    Thanks very much in advance.
2

You need to either find a performance curve or equation for your particular
thermistor from its datasheet, or to measure it yourself. You also then have
to allow for the voltage divider equation to translate thermistor resistance to
input voltage.

For logging data SD cards are often used. There are data logging shields which
tend to have an RTC as well as SD socket and level translation for the SD card
(which need 3.3V).