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I2C missing on BeagleBone Black

Hi !

I'm trying to develop an application on the BeagleBone Black that uses the I²C bus in order to communicate with a temperature sensor.

There should be 3 I²C buses on the BBB according to the documentation (one of them being sort of "hidden"), and I am trying to use the i2c-2. However, for some reason, this bus seems not to be present. When I try and run "i2cdetect -l" the only output I have is :

i2c-0   i2c             OMAP I2C adapter                        I2C adapter

I have been unable to understand why the i2c-2 bus is not recognized (or mapped). I have set up the BeagleBone following the steps described here, and didn't customize it further.

Thanks in advance for the help !

Cyril

  • You will need to initialize the I2C bus you need and setup pinmux for it.

  • Biser Gatchev-XID said:

    You will need to initialize the I2C bus you need and setup pinmux for it.


    One of the most frustrating things about technical forums is when an employee posts an answer that just says "You need to do the right thing"...  Clearly this user is here because they don't know what the right thing is.  The Device Tree mechanisms are very much, undocumented magical incantations for most people.  What would be best, is if you would point this user at a complete device tree specification for the BBB that works, or to provide the sections of the .DTS that need to be added, in context with the surrounding pieces identified.

    I was hoping to come to the forums to find out why I can't get my Panda Board derived, custom board's i2c4 to work, and to recognize the connected i2C-AI418S to be recognized.  But, after seeing this reply, I'm not sure that even TI employees have any idea how to make their stuff actually work with the device tree specs.

    And yes, I am being harsh, but really, people are wasting 100s of hours of their own time investigating this stuff and getting no where fast due to the lack of detail available on the device tree subject matter.


    A simple search of the internet shows countless posts about exactly how to make device tree specs do the right thing.

  • Greg,

    Thanks for your comments, we appreciate it.