thermistor, microcontroller

Thread Starter

shankar M

Joined Mar 27, 2014
16
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?
 
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?
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?
 

ericgibbs

Joined Jan 29, 2010
21,439
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?
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
 
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
I like that!
 
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