Introduction: Arduino Thermistor

Figured i would share my program with others who might find it useful.

and if some of you find faults, please give me feedback ! =)

what you need for this project:

1 x 10kOhm resistor.

1x 50kOhm thermistor.

1x Arduino.

Step 1: Scematic and Source - Code.

Download this Source code for arduino from dropbox when you are done wiring up.

Source code: Source code

Also if you want to save the measurements to a file, i've written a little command line program for it using python.

The program: Arduino Serial Python

If you dont have python installed, download and install version 3.5.0 or newer.

Python download: Python

Be sure to register python PATH when installing.

Now if you got it all installed downloaded and ready to go, just click the serial.BAT file and follow the instructions.

Feel Free to give me feedback if you find out something is wrong or if you got some extra ideas! it is appreciated :)

Comments

author
RazanD1 (author)2017-08-09

the files does not oper when i download them can you give another link ?

author
DanielleC4 (author)2016-01-18

Hi! I am making a project on temperature measurements with arduino uno and thermistor. I am using the voltage divider method to determine the resistance of the thermistor, and the steinhart model for temperature calculations. However, when I tested it on a boiling water the resistance obtained by the setup where not the same on the multimeter readings, so that, instead of obtaining a temperature of 100 deg Celsius I obtained higher than that ranging from 101 deg Celsius-116 deg Celsius. Do you have any suggestions on how can I fix that?

author
Mahitchima (author)DanielleC42016-01-21

are you sure that the reading is not right? and how so?
Are you using the technical documents for your thermistor?
Could there be any minor fault in your equation?

could your circuit may get interference from anything?
maybe you have some resistance in your circuit you did not thougth off?
is it soldered together properly, or something like that?

author
DanielleC4 (author)Mahitchima2016-01-26

Not all readings, I obtained larger errors just on the boiling temperature and a minimal difference on the freezing temperature. All parts are properly soldered, BTW on my first post I am using a series resistor with 5% tolerance but I've already replaced it by 1%. And also, I changed my code, instead of Steinhart model (where as I think there may be a problem on the coefficients that I've copied from some codes in the internet that I have shouldn't done as it's different for different brands of thermistors) but for now I am currently using the Simple model (using Beta Parameter given on the datasheet of the thermistor I am using). Now, I have readings of 101-102.7 degree Celsius on the boiling point temperature it is quite closer to the expected readings compared to my initial post, but I am still in trouble since the readings I obtained are not accurate.

I don't think that my circuit gets some interference It is cased on a box. BTW, thanks for the comment. :)

author
Mahitchima (author)DanielleC42016-01-26

As you might have noticed, i have not used steinhart on my instructable, i made a huge array using a python program, then pasted it into my code in the arduino editor. and went from there converting Volt-signals into temperature output.

it was kind of an experimental take on it, but it indeed showed the correct temperatures.

author
Mahitchima (author)DanielleC42016-01-26

alright =) I think if you find the technical data's for your thermistor, you'll find the numbers you would need for correct measurement there :)

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Bio: Transistors may sometimes work nice as firecrackers.
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