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MKW30Z temperature sensor calibration

Question asked by Lucian Firan on Nov 28, 2016
Latest reply on Nov 29, 2016 by EARL GOODRICH

KW40Z_Connectivity_Software_1.0.1 (KSDK_1.3.0) IAR 7.5

 

MKW40Z/30Z/20Z Reference Manual, Rev. 1.2, 10/2015
28.4.8 Temperature sensor     links to

Temperature Sensor for the HCS08 Microcontroller Family (document AN3031).

http://cache.freescale.com/files/microcontrollers/doc/app_note/AN3031.pdf

 

witch presents a calibration implementation:

 

Floating-Point
Calibrated (3 Points) Typical Accuracy ± 2.5degs C
Uncalibrated  Typical Accuracy ± 8degs C

 

Fixed-Point
Calibrated (3 Points) Typical Accuracy ± 12degs C
Uncalibrated  Typical Accuracy ± 18degs C

 

In conclusion having fixed-point arithmetic calibrated and un-calibrated does not help you at all...

 

Having no calibration at all and floating point algo goes to ±8 deg C with is quite hight.

 

3 point calibration gives good result but is hard to achieve in production (as time and resources).

 

In production, one point calibration is the easiest to do - measure by chip and measure by reference thermometer near chip.
(@ room temperature)

 

The HCS08 AN3031 document is accurate on MKW30Z ?

 

Is some sort of calibration implemented in framework ?

 

What would be the Calibrated 1 Point Typical Accuracy ?

 

Thank you,

Lucian

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