How to set up multiple w1-gpio for a capeless BeagleBoneBlack?

I've spent the last few days hacking my way through a thick jungle to
figure out how to create a device tree or whatever I need to configure
one or more pins on a BeagleBoneBlack with Angstrom to talk one-wire
(with the w1-gpio driver, I presume). Can anyone give me some hints?
I'm still wrapping my head around device tree (why aren't the source
files included in the image? or are they?), pinctl, bone_capemgr,

There don't appear to be any examples of one-wire usage in the device
tree source files I find in the Angstrom build tree, e.g. here:


Thanks in advance!


Beauty. Thank you!

Okay, there's a few things I'm having trouble parsing, though they
became a lot clearer when I read the contents of:


(with the overlay discussion, in particular):

    * Copyright (C) 2012 Texas Instruments Incorporated -

   Hi Russell From what I've seen at
I suspect that gpio2 points to the P8 header and 3 to pin 3. I
think the last 0 is a flag for parasitic power, which is not

gpio2 is that the BBB_SRM seems to call gpio1 (0-3, inseat of 1-4).
Table 10 of the BBB_SRM says mode 7 of P8 pin 6 (mux mode 7) is
gpio1_3, which seems to translate the the <&gpio2 3 0>. Section 8 of
that document tells you which pins are in use for onboard devices.

   Have you managed to get the module loaded? I have managed to
install a 3.8.3 kernel onto my BBB and have some w1 modules,
none of which are w1-gpio. I built the kernel using git clone

   But I'm lost as to what to do to get a w1-gpio kernel module
out of it. Can you point me at any documentation that that
explains the device tree, or something that helped you get
further along the path to getting w1-gpio working

The issue is that the beaglebone black is using the pin defined in the
the weather cape device tree overlay thing for eMMC. So, it's
necessary to pick a different pin and modify the device tree

It looks like pin 11 will work, so the gpio switches to <&gpio2 13 0>
and the 0x0c changes to 0x34.

Here's what I did to get a one-wire bus working on BeagleBone Black.
I created (modified from the weather cape's) a DTS file:

  * Copyright (C) 2012 Texas Instruments Incorporated -

Thank you Russell. I’ll hopefully find some time later this week to try that out. Still getting my head around the build system etc, it’s more like a learning wall than a curve at moment.



Wow it works.
You’ve made this too easy. Thank you again for your help.