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
Solved! Go to Solution.
Iva
I am using the FRDM-K22 board and the the KSDK2.0 rtc_func demo ("C:\Freescale\KSDK_2.0\boards\frdmk22f\demo_apps\rtc_func").
This uses the eternal 32.768k osc.
But maybe the osc is not 20PPM as advertised.
I realize this is not a KSDK topic so I will mark this as corrected.
Thanks
Joe
Hi joe birch,
please use external clk for RTC because internal oscillator is not very accurate.
You can trim accuracy by using external capacitors.
I hope this helps you.
Have a nice day.
Iva
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Iva
I am using the FRDM-K22 board and the the KSDK2.0 rtc_func demo ("C:\Freescale\KSDK_2.0\boards\frdmk22f\demo_apps\rtc_func").
This uses the eternal 32.768k osc.
But maybe the osc is not 20PPM as advertised.
I realize this is not a KSDK topic so I will mark this as corrected.
Thanks
Joe