Nuke in a non-Arbotix context?

[Joel Dillon]

I've got a Bioloid Comprehensive Kit, assembled as a King Spider, and
a USB2Dynamixel. I'm interested, eventually, in having a hexapod with
a Fit-PC2 on it as a controller; in the meantime I'm controlling it
via a Linux PC and USB cable.

Nuke looks very interesting, but I'm not especially interested in
using an arbotix. How much of a challenge is it likely to be to modify
Nuke's output to incorporate into a Linux program? The talk of
capturing poses in particular concerns me since I don't know how that
would work without an arbotix.

[Fergy]

Originally, I intended to support the USB2Dynamixel as an alternate
pose/capture device -- however, we've found that often doesn't work
well. The issue is opening a port at 1MBps in Python, fails on many
systems.

The python interface also only does some very basic capture/pose, and
the most basic of the IK -- there's no gait engine on the python side,
you'd have to port a number of items back from C.

-Fergs

[Fergy]

I should also point out, the Python side code is very slow -- it's not
optimized at all, because we have to make it so universal. The
exported C code for the ArbotiX is quite optimized however.

Why exactly are you "not especially interested" in the ArbotiX?
Because you have a USB2Dynamixel? I've recently been designing a
rebuild of my bot, Issy, that would be FitPC powered (but he won't get
built until after Mech Warfare next month). I'm intending to have an
ArbotiX on there, because I can offload the IK computation (just send
X,Y, and rotation speed), and also use the ArbotiX to interface to
sensors. Are you planning to put any sensory on your bot?

-Fergs

[Joel Dillon]

On Mar 11, 3:20 pm, Fergy <mfer...@gmail.com> wrote:
> Why exactly are you "not especially interested" in the ArbotiX?
> Because you have a USB2Dynamixel? I've recently been designing a
> rebuild of my bot, Issy, that would be FitPC powered (but he won't get
> built until after Mech Warfare next month). I'm intending to have an
> ArbotiX on there, because I can offload the IK computation (just send
> X,Y, and rotation speed), and also use the ArbotiX to interface to
> sensors. Are you planning to put any sensory on your bot?

Pretty much, yes. If I've already got a full-power PC on there then
the only reason
to add a microcontroller would be to add analogue sensors. I suppose
that might
be a reason to add an ArbotiX, but I don't have one at the moment and
I wouldn't
be using most of the functionality (motor drivers, servo headers and
so on) so it
seems a bit of a waste.

At the moment, though, I'm mostly messing around with machine vision,
which
I'm doing with a couple of USB webcams that go into a PC.

It's mostly the generated C code I care about; I'd be trying to port
that to Linux.
The Python stuff, I'm only worried about insofar as I can get it to
generate that code
without an ArbotiX to talk to. I should probably also mention that I'm
comfortable
with C/C++ stuff (it's my day job) but I've never really messed about
with Python.

[Joel Dillon]

Ok, after spending lots of time trying to make things work, I finally
broke down and bought an ArbotiX. :)

I note that http://code.google.com/p/arbotix/wiki/DevelopmentTimeline
says that release 0013 will fix some problems with hexapods - but that
doesn't seem to be available for download yet? Am I signing up for
frustration if I try and use the current release for a hex?