Hi NV,
When I plug in RTC coiincell on our Jetson Orin Nano custom carrier board before main power supply connectted， the RTC timer will work or not？
Since I test that the start time is1970-1-1 8:00:00，when plug only RTC coincell，the RTC timer will not work unless main power supply is connected and system boot-up。
Jasper
20241211
Please make sure R560 is mounted on your board. You can refer to the carrier board P3768_A04 files in DLC to check that.
Hi NV
R560 is on board，we are now testing our custom carrier board with same circuit as P3768. My question
is RTC timer will work when both RTC cell is on AND power-on behavior is triggered to let RTC circuit start running, am i right?
jasper
20241216
RTC can work with cell only.
你好！
我的意思是板子先装RTC，但是不开机，这个时候RTC有没有跑？
我试过只装RTC，初始时间是1970-1-1 8:00:00，如果不开机，RTC时间不在走； 要开一次机，RTC时间才会走。
jasper
20141216
You need boot to system to sync the time otherwise it stay in default define time.
Thanks
Hi NV,
a new problem occur with our carrier board(RTC circuit same with devkit) and Jetpack 6.1(R36.4）, after RTC time once writen by hwclock -w, then RTC time could not be read out by hwclock -r. Is that right? or use timedatectl command to read RTC time?
Jasper
20241219
Get the detail by --verbose.
sudo hwclock -r --verbose
How about RTC1
sudo hwclock -r -f /dev/rtc1 --verbose
Could you get the rtc information.
sudo dmesg | grep -i rtc
please make sure you are using RTC0 but not RTC1.
yes，default is RTC0（RTC0 is PMIC RTC， RTC1 is CPU RTC）
BTW，how to make sure we are using RTC0 on Jetpack 6.1?
For Jetpack 5.1, we did not found this issue with same PCBA board.
If your /dev/rtc is linked to rtc0, then it is using RTC0…
More suggestion to deal with RTC0 readout timeout issue?
Is your issue reproducible with NV devkit?
Hi Wayne,
this issue somtimes happen， not reproducible every time.
Today I test again，till now I have not yet met that.
We will keep testing, thanks for you advice.
