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This is the screen when I connect a new beaglebone green with an rtc.

If I burn the latest image, the beaglebone does not detect the rtc.

El jueves, 22 de marzo de 2018, 23:38:03 (UTC+1), Jeff Andich escribió:
>
> I'm working with the RTC (MCP794110) at the moment, but on a "BB-X15 - 
> like" custom board platform.
>
> I'm not sure I follow. your post.. What's the I2C tool? Are you talking 
> about attaching the RTC to the BBB via the I2C tool or a problem with 
> reading the RTC on the BBB? Pardon my ignorance but does the BBB come with 
> an RTC (e.g. MCP794110) installed?  The BB-X15 does..
>
> Did you enable the I2C bus the RTC is attached to in the dev. tree? On my 
> platform, I had to enable the I2C bus (I2C3) in the dev. tree before the 
> drivers for the RTC would load.
>
> Then with some "new" RTC's on some of my boards, but not all, I got 
> "unable to read the hardware clock, I think, when the kernel is attempting 
> to set the system clock from the hardware clock (see the following):
>
> ebian@BeagleBoard-X15:~$ dmesg|grep rtc
> [    1.551522] rtc-ds1307 2-006f: rtc core: registered mcp7941x as rtc0
> [    1.551652] rtc-ds1307 2-006f: 64 bytes nvram
> [    1.554511] omap_rtc 48838000.rtc: rtc core: registered 48838000.rtc as 
> rtc2
> [    1.558261] palmas-rtc 48070000.i2c:tps659038@58:tps659038_rtc: rtc 
> core: registered 48070000.i2c:tps659 as rtc1
> [    1.997160] rtc-ds1307 2-006f: hctosys: unable to read the hardware 
> clock.
>
> From what I've read on posts involving the RTC the following messages:
>
> 1) "unable to read the hardware clock" message and  the 
> 2) hwclock: ioctl(RTC_RD_TIME) to /dev/rtc to read the time failed: 
> Invalid argument.
>
> are due to the RTC's time being not initialized or (?invalid?).  I've been 
> able to work-around this by setting the clock, but initially I get warning 
> #2 when I initialize the clock with a valid date/time.  I'm wondering if 
> anyone can confirm if this is the correct fix for this scenario...
>
> Also, when PTC builds the BB-X15, and the BBB manufacture builds the 
> BBB's  (assuming BBB's have a RTC installed), do they ensure that the RTC 
> is correctly initialized prior to shipping to the distributors ?
>
>
> On Wednesday, March 21, 2018 at 6:18:27 PM UTC-5, Graham wrote:
>>
>> Do you have pull-up resistors?
>>
>> --- Graham
>>
>> ==
>>
>>
>> On Monday, March 19, 2018 at 8:28:51 AM UTC-5, Paco Velasco wrote:
>>>
>>> When I connect the rtc it does not detect the 68 address (I2C Tool).
>>>
>>> I have test with 2 RTC diferent,and with the BBB I have no problem.
>>>
>>> Anybody knows what could be the problem? Thanks
>>>
>>>

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