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News: Glomation introduced new wireless ready low cost GESBC-9260S
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Read January 08, 2009, 07:16:38 PM #0
xfactor69

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unable to read the hardware clock
rtc-at91sam9 at91_rtt.0: hctosys: unable to read the hardware clock

Will a battery fix this or do I need to do something else?

Thanks,
ml
 
Read January 09, 2009, 12:51:09 PM #1
admin

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Re: unable to read the hardware clock
The RTC will not be in an uninitialized state at power up if no back up battery is present.  The current kernel driver does not initialize the RTC.  You can hwclock -w command to initialize the RTC.
 
Read January 09, 2009, 03:46:49 PM #2
xfactor69

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Re: unable to read the hardware clock
[01:45 PM root MicroPrism /etc]$ hwclock -w
Cannot access the Hardware Clock via any known method.
Use the --debug option to see the details of our search for an access method.

[01:45 PM root MicroPrism /etc]$ hwclock -w --debug
hwclock from util-linux-2.12r
hwclock: Open of /dev/rtc failed, errno=19: No such device.
No usable clock interface found.
Cannot access the Hardware Clock via any known method.
 
Read January 09, 2009, 04:20:46 PM #3
xfactor69

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Re: unable to read the hardware clock
Does the battery insert with + up or - up.  The manual doesn't show an orientation and the board has no mark to indicate?
 
Read January 11, 2009, 08:18:14 PM #4
admin

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Re: unable to read the hardware clock
The Linux kernel RTC driver is not fully compatible with Debian hwclock if the RTC was not initialized.  Please use the hwclock applet from the supplied Busybox.

The top of the battery holder is + and the center pad is ground.
 
Read March 18, 2009, 06:13:07 PM #5
Gabriel

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Re: unable to read the hardware clock
Hi

I put a battery in my GESBC-9260, started it up, and
1 - set the current date and time using date
2 - copied the system date/time to rtc using hwclock -w
3 - confirmed that the clock is right using hwclock command

I then restarted the system. logged in and tried
 hwclock -s

The system responded
 hwclock: RTC_RD_TIME: Invalid or incomplete multibyte or wide character

Is there some other step I should take?
I am using kernel 2.6.27.4

Regards

Gabriel
 
Read March 19, 2009, 10:41:51 AM #6
admin

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Re: unable to read the hardware clock
Make sure the battery is inserted right.  If you have an voltmeter please check the voltage across C48.  It should read 1.8V.
 
Read March 19, 2009, 12:09:41 PM #7
Gabriel

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Re: unable to read the hardware clock
Quote from: admin on March 19, 2009, 10:41:51 AM
Make sure the battery is inserted right.  If you have an voltmeter please check the voltage across C48.  It should read 1.8V.

Thanks for the help.  I measured 0V.  It turns out the battery was inserted right, but it did not make contact at the bottom.  With a drop of solder on the bottom contact, all is well now !!!
 
Read March 19, 2009, 12:44:33 PM #8
Gabriel

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Re: unable to read the hardware clock
With the battery installed and working, I'm wondering, how long does it last?

I know my battery capacity is 35mAh, but I do not know

(1) how much current is drawn from the battery while the system is powered?
(2) how much current is drawn from the battery while the system is not powered?

Have you done any tests or projections about how long the battery can run the clock?
 
Read March 19, 2009, 03:12:22 PM #9
admin

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Re: unable to read the hardware clock
The RTC will not draw any current from the battery when the board is powered up.  The RTC draws 2uA current and the voltage regulator draws about 10uA.  The battery should last for at least 7 months without power up.
 
Read July 08, 2009, 01:49:56 PM #10
johns

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Re: unable to read the hardware clock
Can't set time date on my 9260.
Kernel Version 2.6.27.4

I verified that the voltage across c46 is correct.

I input from my terminal---
GESBC:/var/log# hwclock --show --debug

hwclock from util-linux-2.12r

hwclock: Open of /dev/rtc failed, errno=19: No such device.

No usable clock interface found.

Cannot access the Hardware Clock via any known method.
   

During boot--
rtc-at91sam9 at91_rtt.0: rtc core: registered at91_rtt as rtc0

rtc-at91sam9 at91_rtt.0: rtc0: SET TIME!

i2c /dev entries driver

TCP cubic registered

NET: Registered protocol family 17

RPC: Registered udp transport module.

RPC: Registered tcp transport module.

rtc-at91sam9 at91_rtt.0: hctosys: unable to read the hardware clock
 
Read July 08, 2009, 02:36:38 PM #11
admin

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Re: unable to read the hardware clock
As mentioned in previouse posts the current kernel driver doesn't handle the RTC well if the RTC is not initialized properly.  The work around is to use Busybox hwclock applet to write the RTC to put the on-chip RTC in an initialized state, busybox hwclock -w.
 
Read July 08, 2009, 03:14:41 PM #12
johns

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Re: unable to read the hardware clock
I read that post but I guess I don't understand it.
I performed the following as suggested.
GESBC:/dev# busybox hwclock -w
-bash: busybox: command not found

As you mentioned in an earlier post I performed --
GESBC:/dev# hwclock -w
Cannot access the Hardware Clock via any known method.
Use the --debug option to see the details of our search for an access method.

So .. I installed busybox apt-get install busybox
then
GESBC:/dev# busybox hwclock -w
hwclock: applet not found

« Last Edit: July 08, 2009, 03:22:09 PM by johns »
 
Read July 08, 2009, 03:53:49 PM #13
admin

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Re: unable to read the hardware clock
Not sure how the Busybox from Debian was configured maybe hwclock was not part of the build.  If you still have the factory installed file system then you can just simply use the hwclock -w to write to the RTC.
 
Read August 26, 2010, 04:01:55 PM #14
mimmus

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Re: unable to read the hardware clock
Final solution is to check if you have devices or make it:

cd /dev/ && mknod rtc0 c 254 0 && ln -s /dev/rtc0 /dev/rtc

then follow this link:

http://www.at91.com/forum/viewtopic.php/f,12/t,18543/
 
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