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9 years, 2 months ago.
RTC connection for FRDMK64F
Dear All,
I have a FRDMK64F board and want to get the data and time contentiously even after power off.
It means needs to maintain the power for RTC section through supply the voltage via RTC_BAT. How can I connect RTC battery to FRDMK64F board for time preserving.
Regards, Titus S.
1 Answer
9 years, 2 months ago.
There is a header connector 'J23' marked VBAT on the bottom of the board. That links the P3V3_K64F power to the RTC section. You will need to carefully cut the copper track between the connector pins and connect a 3v back up cell +ve to pin 1 and -ve to a ground point somewhere on the board.
Hi Paul, Thanks for your support. I've used "3V CMOS battery cell" and not able to retain the date and time but succeed with powering up the RTC section through RPS 3.3V (regulated power supply). Is there any voltage specifications for RTC section that we need to use 3.3V exactly or more ?
Also I've checked the following data sheet, page no 7 and it was mentioning that we can use 1.71 to 3.6V But it is not working in my case.
http://cache.freescale.com/files/microcontrollers/doc/data_sheet/K64P144M120SF5.pdf
posted by 16 Mar 2015
I am very interested as well, what's going on here?
posted by Vladimir Akopyan 31 Mar 2016And why would you not bring out the battery to the header, that's where it belongs! Or add a holder for it, damn.
posted by Vladimir Akopyan 31 Mar 2016Yeah, you are right. It would be good if they designed like that. As Paul told, I've done the changes in my board and working flawlessly till now.
posted by Titus Stalin 01 Apr 2016