Need help making a thermistor lookup table

Hey all,

Need help making a thermistor lookup table for Marlin.

It is for NTC Thermistor P/N 104JG1J (http://www.digikey.com/product-search/en?x=-1030&y=-71〈=en&site=us&KeyWords=615-1020-nd)

I was trying to use the following site to create the table but not sure of all the values I am supposed to use....

[calculator.josefprusa.cz]

I am using the Ramps 1.4 with marlin firmware

Thanks for any help!

I can't find the datasheet for the 104JG1J, but hopefully the datasheet for the 104JG1K is similar enough. The resulting table is attached.

That should work, but how did you generate the table and what values did you use?

There are two ways.

For the calculator you linked:

R0 and T0 are a resistance/temperature pair taken from the data sheet. Normally the 25C values.
Beta is taken from the data sheet.
R1 = zero , I don't think any current reprap electronics have an R1.
R2 = the sense resistor from your electronics, which is 4700 ohms as standard.

But a more accurate way is to use the script from this article:
[hydraraptor.blogspot.co.uk]

You need python installed on your computer, which you already do if you use skeinforge or printrun. The easy way to use it is to load it in IDLE and alter the parameters directly. This script takes three resistance/temperature pairs, as well as the value of the sense resistor on your electronics, which again is normally 4700 ohm.