RTC clock battery for the Orin dev kit

Autonomous Machines Jetson & Embedded Systems Jetson AGX Orin
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25

…You didn’t upgrade your system…this is still jp5.0 DP.

The RTC0 is only supported in jp5.0.2…

26

I had previously followed the instructions on Jetpack 5.0.2 with Jetson Linux 35.1 is now live! to do my upgrade but missed the part above the commands about editing the file in /etc… I redid it today and it caused the system to boot with all kinds of errors, no display so I’m going to wipe it and start fresh. I’ll post my results tomorrow once I have things reinstalled.

27

Hi,

That issue is out of rail of the original topic of this post. If you hit issue in boot, I would suggest directly reflash the board with sdkmanager.

28

I reinstalled with 5.0.2 and there were some errors. I tried a few times but SDK manager always said that install failed. It seemed that there were issues with several packages. A quick googling seems to indicate that it may be because I had installed a different version of things like OpenCV on that computer. The Orin would boot though so I tried switching the symbolic link to /dev/rtc0 but it still didn’t retain time after a reboot. I have other work that I need to be doing and this is turning into a big distraction so I am going to step away from this one for now.

29

Hi,

Please change the udev rule ( /lib/udev/rules.d/50-udev-default.rules) to below

This solution has been confirmed by other users.

SUBSYSTEM==“rtc”, ATTR{hctosys}==“0” , SYMLINK+=“rtc”
SUBSYSTEM==“rtc”, KERNEL=="rtc0 ", SYMLINK+=“rtc”, OPTIONS+=“link_priority=-100”

30

I failed the procedure.
I changed rtc0 to a symbolic link.
Is there a way to restore rtc0?

rtc → rtc1
rtc0 → rtc
rtc1

31

You can just see the answer right before your comment…

1 Like
32

Thank you for your response.
I did not understand the content of your previous comment.
I changed the udev rule and it works as expected.

rtc → rtc0
rtc0
rtc1

However, when I reboot, the system time is set to 2022/4/22.
Is there something else that needs to be done besides the battery connection?

33

Hi,

The system time set to 2022/4/22 is an issue directly from ubuntu timesync service.

We cannot help this. The solution maybe write another service to sync up your system time with RTC clock in every boot.

34

I explained similar thing to another user last week.

Please take a look.

1 Like
35

Hi, I followed the guide. I use Jetpack 5.0.2, I have battery connected and I changed 50-udev-default.rules but I still have an issue with proper time keeping. After I set the time manually and power off and on the system the time is kept only in RTC. When I try to sync it to Local time and Universal time shown by “timedatectl” it doesn’t work. “sudo hwclock --hctosys” gives me “hwclock: Cannot access the Hardware Clock via any known method.” And time is not synchronized. Can you please help me to fix it?

hwclock --verbose
hwclock from util-linux 2.34
System Time: 1650548033.593276
Trying to open: /dev/rtc0
No usable clock interface found.
hwclock: Cannot access the Hardware Clock via any known method.

EDIT: Today I get:

root@ubuntu:/home/jetsonorin# hwclock --verbose
hwclock from util-linux 2.34
System Time: 1650545823.016839
Trying to open: /dev/rtc0
Using the rtc interface to the clock.
Last drift adjustment done at 1661946454 seconds after 1969
Last calibration done at 1661946454 seconds after 1969
Hardware clock is on UTC time
Assuming hardware clock is kept in UTC time.
Waiting for clock tick...
hwclock: select() to /dev/rtc0 to wait for clock tick timed out
...synchronization failed
36

Hi @vojta.micek,

Please help to open a new topic if it’s still an issue. Thanks

37

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