Matrix user forums

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

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

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