Re: BeagleBone Black and GPIO issues

[Brook Milligan <brook%nmsu.edu@localhost>]

> On Oct 11, 2024, at 5:17 PM, Dr. Nicola Mingotti <nmingotti%gmail.com@localhost> wrote:
> 
> I am using this table, from my notes, i used it for many years with
> different OS (debian & freebsd) it is reliable AFAICanSay.

Yes, but …

As you are discovering, each kernel can probe differently so sometimes you need to look at the details.  I, too, found this out the hard way by experimentation after naively using the documentation for other systems.

> It is taken from a book, author and page are written near the table.

If you want a reasonable reference for the BBB, Derek Malloy’s book is pretty complete.  There are some tables of his regarding the gpio pins that can be really helpful.  (Just make sure you know which gpio device is which in the kernel).  See

	https://github.com/derekmolloy/boneDeviceTree/tree/master/docs

> I would say, that CURRENT is at a good point, but the pull-up/
> pull-down feature needs to be there, it is important.

I did not know that -current now gets the devices right.  That is great.

Anyone else: why?  Is that because the device trees were changed?  Something else?

Yes, it would be really helpful to have all the pull-up/pull-down/etc. states of the pins reported or at least discoverable via gpioctl.  Anyone have an idea how to do this?

In the meantime, they can be figured out as I mentioned before and they work reliably.

> Or, i can try, but I need assistance ;P

Feel free to ask.  I think we are all happy to help.

Cheers,
Brook