Hi Andy!

Short answer. Only the 3/2017 image works correctly for Libroboticscape,
RCPY, Jhonny5, and node-robotics cape. And even then with the node red,
most of it doesn't work at all. RCPY is just conversion of the
libroboticscape, but most of the functions aren't there from the
libroboticscape. Newer 4.x kernels simply won't work.

Long answer.

The folks who designed the board use it for a class in a class at a
university. As such, Robert C Nelson has disabled overlays for the Blue
board. He also as of this point hasn't updated the code to pull out all of
the pinmuxes in newer boards despite protests from several of us so far.
again because he doesn't want top break the code the school uses if the
board is accidently updated. The BBBLue also pulls out some pinmuxes that
aren't standard on a normal beaglebone, and assigns them under a different
nomenclature than a normal Beaglebone. This is important later.

The libroboticscape library uses some older coding and very specific coding
to perform some back end wizardry to handle the 4th encoder & the servos.
this eliminates the ability to use them without the library. the Analog
pins are also handled via mmap, which means you can't get to them from
python. This library is also called for the battery checker. RCPY is
another university class grade piece of code, and largely unmaintained as
you'll find. unfortunately, to use everything and use it easily/correctly,
this library is required. In python especially, there is no way to use the
Analog pins, or even read from them. using the "State" in RCPY and in any
of even the "C" examples is blocking, meaning that you can't run two
instances with it, it'll close the first so the second. with some kajigery
i was able to get some things out of it, right or not. it's working for me
so far.

Adafruit BBIO uses a certain nomenclature when setting pinmuxes. this is in
the format of "P8_8", and it's hard coded. This is because the underlying
software for setting the pinmuxes to do things is also hard coded for this
style that the Adafruit BBIO uses under everything. the non-standard
nomenclature of some of the pinmuxes means you can't access them via this
python library.

The node-roboticscape is based on an even earlier piece of code that's no
longer supported by node-red. as such, most of it's corresponding functions
aren't even available. Johnny5 looks for things exported to
/sys/class/gpio, which aren't there because the overlays pinmux things
instead. You can export pins in this directly, but all PWM is handled via
pinmuxing and the PRUs.

Between the 3/2017 and the newer versions of the kernal, the pru driver
changed. so newer kernel functions for PRUs doesn't work correctly. This
includes encoder #4, and all servo pins.

Now, with all of the depressing things out of the way that inhibit the use
of it on newer kernels, there is a newer version of libroboticscape in the
works. how it will function is beyond me and the developer isn't responding
to inquiries so far after over a month. it does appear Robert C nelson is
helping them at least.

I myself am not willing to give up on this thing just yet. I'm on the
3/2017 kernel.none of the others work, or provide complete functionality,
including the debian and ROS images. i'm not fluent in C and i bought this
thing to do some fun things with my daughter, which means python for me.
i've done some things to get the functionality i want and use a variety
silly things to get it, but i can at least get some of the things needed to
make it all work. if any of it is of interest to let me know, and i'd be
happy to share what i've done to get it going. there are likely easier
ways, mostly tied to learning how to create a better, more complete version
of RCPY, but it's all well outside of what i know how to do on such a large
scale.

Thanks!
Drew







On Thu, Apr 5, 2018, 7:34 AM <[email protected]> wrote:

> Hi Drew,
>
> Have you had any luck with this so far?  I've hit the same point (which is
> how I came across this post).
>
> If it's not possible to get the robotics cape, rcpy/pyctrl, node-roboticscape,
> etc. working with the "current" image, I'm happy running an older image.
> It might be helpful to have a warning in any Blue-specific documentation
> that the newer images should be avoided until things are better.
>
> Any recommendations for an older image where things like the EduMIP robot
> examples will work?
>
> Thanks!
> Andy
>
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to a topic in the
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit https://groups.google.com/d/
> topic/beagleboard/GHeMjrAM5AE/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> [email protected].
> To view this discussion on the web visit https://groups.google.com/d/
> msgid/beagleboard/9bdd6e4b-6ea3-44e9-a4d6-3300a5bfdae6%40googlegroups.com
> <https://groups.google.com/d/msgid/beagleboard/9bdd6e4b-6ea3-44e9-a4d6-3300a5bfdae6%40googlegroups.com?utm_medium=email&utm_source=footer>
> .
> For more options, visit https://groups.google.com/d/optout.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/d/msgid/beagleboard/CAMb-tS%3D8v4QW9pO6nT1nrfyxjLB8M2zKB_qOAYTGuO7ydjFE9g%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.

Reply via email to