Using Beaglebone Black(BBB)Rev C, Chronodot(ds3231) rtc via i2c, and Ubuntu 
14.04 armhf 4.4.0-armv7-x2 (Robert Nelson's armhf site). 


I can get i2c recognition by BBB at 0x68 as expected with i2cdetect.  
Registration seems to work using echo to new device on i2c-2, since it 
comes up with a cat command.  I can set hwclock and check with cat   
/sys/class/rtc/rtc1 file and all seems fine, until I do a cold reboot.  
Then everything reverts to Jan 15 01:01:00 2016.  I am booting from an SD 
disk instead of onboard.

With regard to rtc, a check on dmesg gives me a reversion back to the rtc0 
, 

"[ 3.748545] omap_rtc 44e3e000.rtc: rtc core: registered 44e3e000.rtc as 
rtc0"
then

"[ 3.867388] PM: bootloader does not support rtc-only!"


[ 4.220591] omap_rtc 44e3e000.rtc: setting system clock to 2000-01-01 
00:00:01 UTC (946684801) 


Here you can see my manual entries:


[ 2481.604507] rtc-ds1307 2-0068: SET TIME! 

[ 2481.608512] rtc-ds1307 2-0068: rtc core: registered ds3231 as rtc1 

[ 2481.608866] i2c i2c-2: new_device: Instantiated device ds3231 at 0x68 



My questions :  Why or how does the rtc instance get written over at boot?  

Could this be a bootloader issue?  

Is it a driver issue with Ubuntu non-support(states same as ds1307)?

          I2c issue?

          Or will the Chronodot simply not work with BBB and Ubuntu?

Note:  Skill set- advanced newbie; not fresh newbie, but too hacking 
dangerous to ever be an expert!
Thank you in advance for any insight that you may have.

B2256

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/beagleboard/9e613420-9644-4603-81e6-f4d0e1171f7a%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

Reply via email to