Hello,

I had the same need and try to change my RS485 cape into a 232 one on my BB 
White.
I have the folowing issue :
the command  cp eeprom.new /sys/bus/i2c/devices/3-0054/eeprom failed due to 
connexion timeout.
When trying some commands with i2ctools, the ressource device seems to be 
busy.

Any idea about what I missed ?
Thanks a lot for any help.


Le jeudi 3 octobre 2013 07:46:35 UTC+2, Jesper We a écrit :
>
> Sure, here it goes:
>
> First of all, the CANBUS, ProfiBUS, RS232 and RS485 capes from 
> Beagleboardtoys all share the same PCB. It's just different components 
> mounted, and different jumpers configured.
> So what I did to the hardware was to unmount the 5 jumpers connecting the 
> CANBUS chips to the UART and connector, and instead mount them to connect 
> the RS232 driver chip, which I also mounted.
> Yes, hand soldering 0402 chip components is not for the faint of heart, or 
> for those with un-sharp soldering irons. I have plenty of experience and a 
> MIL-SPEC soldering certificate....
>
> So now the software part: The only thing that is important for the kernel 
> cape manager is the board part no and revision no in the EEPROM. The EEPROM 
> format is specified in the BB System Reference Manual, except for one thing 
> that is missing: It says the part number is 16 bytes. If you have a part no 
> shorter than 16 bytes you need to pad it with "." characters. I wanted to 
> use a .dts file that was already available in the Angstrom distribution, so 
> I called my cape a "BB-UART1........" of revision A0.
>
> I had some trouble trying to edit the eeprom directly, probably because 
> the editor tried some smart way of saving that a Flash memory driver didn't 
> like... so I made a copy, edited, and then copied the content back:
>
> cp /sys/bus/i2c/devices/1-0054/eeprom ẽeprom
> vi -b eeprom
> ....make edits in  Replace mode....
> cp eeprom /sys/bus/i2c/devices/1-0054/eeprom
>
> The copy into the eeprom takes a LONG time. I2c is not a fast thing...
> Also notice I used vi in binary mode. You can use any binary file editor, 
> even hexedit :-) 
>
> Now with a correct board part no and revision the kernel will 
> automatically load the driver at boot.
>
>
> On Wednesday, October 2, 2013 7:53:09 PM UTC+2, garyamort wrote:
>>
>> A brief writeup on what you did would be nice so others have more 
>> concrete steps beyond my vague "it's somewhere in the directory tree".
>>
>

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