2 Replies Latest reply on May 19, 2015 11:18 PM by postITnote

    Thermistor Value Issues - accurate on UNO, different values on Edison

    postITnote

      Hello!

       

      I am using the Arduino breakout with Windows 7 and uploading using the Intel Arduino IDE.

      The thermistor I am using is a salvaged meat probe with a voltage divider circuit.

       

      I can read the thermistor, calibrate it and test it with a bought digital thermometer using an Arduino UNO with no problems.

      Then I go to the Edison powered Arduino BB, plug it in and use the same code. The readings are off by 100 when I run it through an equation to obtain the Kelvin values. The values are also off by varying degrees of discrepancy when I use code with the Edison that reads out Celcius and Fahrenheit. I've tried changing the fixed resistance value (hardware and software) in the voltage divider circuit, the Beta value and changing the ADC from 1024 to 4096. As well as different ways to calibrate the sensor.

       

      I'm hoping that if I can figure out why there is a discrepancy, I can fix the code to reflect that. 

      Has anyone encountered a difference between their analog readings while testing the same sensor on an Arduino and Edison?

       

      Thank you!