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TerryC65
Posts: 151
Joined: Sat May 09, 2015 7:50 am
Location: Wimborne, Dorset, UK

Yet Another Problem with RASClock

Wed Oct 30, 2019 11:02 am

Hi,

I've posted previously about using RASClock at a our local Model Town on a couple of occasions and these give the context of what we are trying to do there: https://www.raspberrypi.org/forums/view ... k#p1467679 and https://www.raspberrypi.org/forums/view ... k#p1422050.

We recently updated our system to Buster and everything seemed to work fine until I noticed that all the clocks were wrong. As outlined in the links, we have a 'master' Pi which is equipped with a RASClock and the remotes all get there time from it using rdate.

When I investigated on site, I found that I got an error from the the 'hwclock' command which said something like 'hwclock: Cannot access the Hardware Clock via any known method.' I assumed that I had made a mistake when building the SD Card for the master pi, so I've just built another here in my home using the same base installation and build instructions as the last one.

When I tested this using a spare RASClock I got an error when sending the command 'hwclock -r' which led me to believe that there was no tick from the clock (I cannot remember the exact error so I then checked the RASClock battery and tried again using 'hwclock -r -- verbose' and got:

Code: Select all

hwclock from util-linux 2.33.1
System Time: 1572431301.386107
Trying to open: /dev/rtc0
Using the rtc interface to the clock.
Assuming hardware clock is kept in UTC time.
Waiting for clock tick...
ioctl(3, RTC_UIE_ON, 0): Invalid argument
Waiting in loop for time from /dev/rtc0 to change
...got clock tick
Time read from Hardware Clock: 2019/10/30 10:28:23
Hw clock time : 2019/10/30 10:28:23 = 1572431303 seconds since 1969
Time since last adjustment is 1572431303 seconds
Calculated Hardware Clock drift is 0.000000 seconds
2019-10-30 10:28:22.366145+00:00
Apart from the Invalid argument in line 7 above, it appears to work now and the hwclock is correct.

Before I go back on site and try this new SD Card, can anyone shed any light on what just happened?

BTW. All the Pis on site are Zeros and are not connected to the Internet and the Pi I used to build the new SD Card is a Pi 3 and has WiFi to my home router.

User avatar
TerryC65
Posts: 151
Joined: Sat May 09, 2015 7:50 am
Location: Wimborne, Dorset, UK

Re: Yet Another Problem with RASClock

Wed Oct 30, 2019 3:30 pm

TerryC65 wrote:
Wed Oct 30, 2019 11:02 am
When I investigated on site, I found that I got an error from the the 'hwclock' command which said something like 'hwclock: Cannot access the Hardware Clock via any known method.' I assumed that I had made a mistake when building the SD Card for the master pi, so I've just built another here in my home using the same base installation and build instructions as the last one.
Apart from the Invalid argument in line 7 above, it appears to work now and the hwclock is correct.
It was an error in the config; the replacement SD Card solved the problem and when I got the old one home, I found a typo in /boot/config.txt
TerryC65 wrote:
Wed Oct 30, 2019 11:02 am
Before I go back on site and try this new SD Card, can anyone shed any light on what just happened?
I'd still be interested in what people may think happened when I tried to build the second card. I made no changes to the card but it suddenly decided to work :?

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