Hello,
We are trying to use the built-in temperature sensor of the TRK-KEA128 dev board, but the values read from the ADC channel doesn't seem to be valid. We are implementing fixed point approximation according to AN3031 - Temperature Sensor for the HCS08 Microcontroller Family. Can be this document applied to S9KEAZ128 MCU or are there any other resources we couldn't find?
Thanks!
Thank you for your answer!
We are doing about the same steps and measuring 40 C in an office with 20-22 C inside temperature. Reading your conclusion that without proper calibration (which is not an option unfortunately) the error could reach 20 C we probably have to look for other options :smileysad:
The chip will naturally have its own 'in operation rise' to consider as well.
I use the ADT75 for my temperature-information requirements anywhere I need better than 'gosh, it sure is hot'... About a buck for the 'A' grade (2C), a little more for 'B' grade (1C).
Actually our goal would be to use as some sort of thermal watchdog, but unfortunately it looks completely unreliable.
AFAIK all 'formerly Freescale' parts use the same basic on-chip temperature process, with 'slight' variations in 25C voltage and slope(s), as detailed in individual datasheets. BUT I am NO FAN of AN3031. You might want to look at my post: