thermistor, microcontroller

Discussion in 'General Electronics Chat' started by shankar M, Apr 11, 2014.

  1. shankar M

    Thread Starter New Member

    Mar 27, 2014
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    0
    Reading thermistor voltage from micro controller ...I have 8bit ADC ..ref voltage 3.3v so rosolation 12.89mV...thermistor temp range 0-50C ... i took 1C =1step is im doing right?
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,447
    3,363
    I don't think so.
    How did you arrive at 1C = 1 step?
     
  3. shankar M

    Thread Starter New Member

    Mar 27, 2014
    16
    0
    i dont no exactly ...i have read in some sites .... how to read help
     
  4. Little Ghostman

    Member

    Jan 1, 2014
    294
    97
    8 bit ADC with 3.3 ref

    256 (ADC steps) / 3.3(ref)=77.57 mV per step

    now idea what the thermistor reads per C the datasheet should give you an idea for given temperatures, but its not going to be 1C per step.
    What micro is it?
     
  5. ericgibbs

    AAC Fanatic!

    Jan 29, 2010
    2,503
    380
    hi,
    Which type of thermistor are you considering.?
    Most common types do not have a linear resistance versus temperature response.

    If you had a linear temperature sensor and you required to it work over a 0C thru +50Cdeg range.

    To give the maximum possible resolution, the sensor signal would need to be amplified.

    If the signal was amplified to give 3.22V for a temperature of 50Cdeg and 0Cdeg equals zero volts, using a 8 bit ADC would give 0 thru 250 Counts.
    ie: [3.22/3.3] *256 =250 counts.

    This would give a temperature resolution of 0.2Cdeg/bit.
    E
     
    Little Ghostman likes this.
  6. Little Ghostman

    Member

    Jan 1, 2014
    294
    97
    I like that!
     
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