AnsweredAssumed Answered

RTC is inaccurate

Question asked by joe birch on Mar 23, 2016
Latest reply on Apr 8, 2016 by joe birch

The RTC is about .02% off (11 secs after 15hrs)

 

I am using the KSDK2.0 rtc_func demo ("C:\Freescale\KSDK_2.0\boards\frdmk22f\demo_apps\rtc_func").

I have tried it on 2 different FRDM-K22F eval boards

 

Board 1: 11 secs fast after 15.5 hrs

Board 2: 7 secs after 15hrs,  22 secs after 40hrs

 

The FRDM-K22F BOM shows the osc is 20PPM

 

Am I doing something wrong?

I know the RTC can be adjusted but it is unacceptable to have to customize this for each board.

 

Please help

 

Joe

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