Raspberry Pi Forums

Posted: **Wed Oct 21, 2015 12:11 pm**

My RTC used to work in Wheezy doing this setup www.cjemicros.co.uk/rpi-rtc , but in Jessie no luck.

I have removed all the stuff I had added to /etc/rc.local
and modified /boot/config.txt to include

dtoverlay=i2c-rtc,ds1307
dtparam=i2c_arm=on

otherwise it's as default

Any thoughts why it won't work ?

Gordon

Posted: **Thu Oct 29, 2015 7:52 pm**

I have it working, as metioned in viewtopic.php?f=45&t=124573&p=836198&hi ... tc#p836198
but I'll add details here too as the thread title is more appropriate.

I have no idea whether it's a good way to do it or just a bodge - I'm sure that those who know will soon say if it's not a good method

As you've done, enable i2c and your RTC in config.txt
Add relevant modules to /etc/modules I have

Code: Select all

i2c-dev
i2c-bcm2708
rtc-ds1307

then following advice on http://afterthoughtsoftware.com/products/rasclock
comment out

Code: Select all

if [ -e /run/systemd/system ] ; then
    exit 0
fi

in /lib/udev/hwclock-set
then set, read and save hwclock

Hope it works for you

Posted: **Thu Oct 29, 2015 8:00 pm**

It's not a "bodge" if it works, it's a "work-around for a new feature". I've got to sit down with my B+ that has the RTC and study what's failing so I can report it on the kernel github.

Posted: **Thu Oct 29, 2015 8:49 pm**

Well, it's still working after several more boots so I'm happy with that.

RTC and Pis seem to have been ongoing issue, many sorted it satisfactorily under wheezy but others still had problems - and there has never been one place to find answers.

It would be really useful to have it sorted once and for all - at least for those of us with RTCs - though I appreciate it's not an issue, and could perhaps be considered a waste of effort, by those who don't

Edit: just a bit of further information...
Before I commented out those lines hwclock was being written to somewhere between shutdown and login as 'hwclock -r' after login always came back with no valid data

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RTC not working in Jessie

RTC not working in Jessie

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