equivalences for thermistor and resistors


I'm programming a 10K thermistor with arduino duemilanove and processing to tweet the temperature every hour. The problem is that the example code that appears in the arduino site for the thermistor assumes that you have a 10K resistor so doing all the math will result in having the temperature in C°.

The problem is that i have only 12K resistors so i don't know how to calculate how much i must substract to the analog input value to get the temperature.

please help!


PS: Sorry for my english! I'm from Chile

I'm new to electronics and arduino aswell so i am probably wrong here but you have an extra 20% resistance so if you times analogue input by 1.2 readings should be correct i think ??

Sorry analogue read goes up with more resistance i think so you should decrease analogue read by 20%. So analogue read times 0.8...

Take your multimeter and measure your thermistors resistance in different temperatures.

Draw points to grid and see, if the line is straight.

Tell us these values, example. 0celcius= 10k ohm. All of them. Maybe we can create something with that.

Cheers, Kari

I have calculated that 926 is 18 degrees Celsius.

Now i have to move the arduino to a place colder or hotter...

EDIT: I typed 96 instead o 926

Try with hot water too, I bet the result is not going to be line, but curve.

Cheers, Kari