Openrov 2.x what is the function of U8?


Hello community,

I would like to load openrov image on sdcard of my Beablebone Black RevC. And start the Cockpit software.
I do not have any controllerboard or openrov hardware, I want to work with the BBB in standalone, it’s just for testing.

On the controller board, there is serial EEPROM U8 CAT24C256, and I understand that it has the function of capemanager for GPIO resources. And perform GPIO pin Mux during boot sequence.

Does the UART and SPI port (those used to communicate with the ATMEGA) and I2C are configured by the contents of the serial EEPROM ?

If yes how do I programm this serial EEPROM (if I install the same) ?

Thank you and best regards.


Hello All

Is nobody able to answer my request (old) concerning the use of EEPROM U8?

Best regards


We put the EEPROM on the controller board to maintain compatibility with the cape spec, and to identify to the BeagleBone which version of the controller board is running. As far as I remember we never actually did anything in the software with this, as the various controller boards (2.5-2.8) kept the same interface to the BBB and to the outside world. We never used the EEPROM for pin muxing.

So if you’re building up a compatible controller board from scratch, or just running the BBB, I don’t believe you need the EEPROM in there.



Hi Walt_Holm

Thank you for this clarification.
But in this case, if this EEPROM is empty, how is USART1 and SPI activated (on the P9 connector) to communicate and program the MEG2560 MCU?

Best Regards.


Hi @romain.reicher:

I’m not a software guy, so I couldn’t really tell you for sure, but I’m assuming that the pin muxing is set in software when the BBB is initialized.



Hi @romain.reicher,

The writeup @Bob_Ellis did for a standalone Raspberry Pi might help. Not having the eeprom was an issue for him too.

Look at the entry on May 29, 2017.

Maybe something similar would have to be done for the Beaglebone.




Here’s the right topic link: