Thermistor clarification

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anzacinexile
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Thermistor clarification

Post by anzacinexile »

I would appreciate please a bit of clarification with the thermistor component or more accurately, how it interacts with the ADC’s.

I understand the components (thermistor and ADC) but if I define the ADC which happens to use a REF voltage of 4 volts and not 5, will that affect the values from the thermistor?

I know that returning a byte from the ADC tops out at 255 but that is at 4 volts for a 4 volt reference or 5 volts for a 5 volt reference so my simplistic reasoning is that if I use a 4 volt reference then the value returned from the thermistor component will be 20% in error.

Either that or I don’t understand the components as well as I thought.

Thanks in advance

Chris

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LeighM
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Re: Thermistor clarification

Post by LeighM »

Hi Chris,
Yes, the component expects full scale readings.
The Vref voltage will need to be the same as the voltage applied to the top of the thermistor/resistor potential divider.
Hope that helps
Leigh

anzacinexile
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Re: Thermistor clarification

Post by anzacinexile »

Leigh

Is there ever a time you’re not working!!!! :)

Many thanks for an excellent and speedy reply. I really do need to use a 4 volt reference (for ADC stability in a very noisy environment) so a bit of maths routine on the byte value from the thermistor is in order I would imagine.

Many thanks again, much appreciated.

Chris

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