DPRG
DPRG List  



[DPRG] Re: robots anyone?

Subject: [DPRG] Re: robots anyone?
From: William Harold Newman william.newman at airmail.net
Date: Mon Oct 2 11:50:12 CDT 2000

On Sun, Oct 01, 2000 at 05:39:09PM -0500, David P. Anderson wrote:
> Eric, what sort of controller are you using on Jeb-dot-double-ought-b?
> I have a new 68332 board made by one of the guys  in the SRS group,
> Kenneth Maxon, that looks pretty cool.  I havent' powered it
> up yet.
> 	http://www.users.uswest.net/~kmaxon/product/products.htm
> 
> but I'm a little nervous about diving in to a robot software development
> mode with cpu hardware that may not be around next year.  What are
> you using?

What about PowerPCs?

I've been thinking about a robot based on a Game Boy camera, a little
RC car, and perhaps eventually an accelerometer, a compass, and/or
another camera pointing backwards. I thought with this approach I
could do a minimum of ME hacking, only a moderate amount of EE
hacking, and have a fighting chance of getting down to software
hacking in a manageable amount of time.

Roughing out how many pixels per second I'd want to think about if the
camera were the primary input, I quickly came to the conclusion that
yes, the vision researchers know what they're doing when they work on
fast computers: I'd want the fastest CPU I could get. Poking around on
the net, it seemed to me that the PowerPC might be a good choice. I
know next to nothing about the PowerPC architecture, but my impression
is that one cycle on a PowerPC tends to do more work than one cycle on
a 68k. And reasonably small, reasonably priced PowerPC microcontroller
boards (e.g. the little PowerPC board from Axiom Manufacturing here,
http://www.axman.com/) run at 40 MHz, while 68K microcontrollers seem
to have slower clock speeds.

The PowerPC might have a further advantage for me, in that I like the
GNU gcc compiler. I looked for information on gcc 68332 support, but
couldn't find anything conclusive; but I know that gcc supports the
PowerPC.

I don't know how different the 68332 programming model is from other
members of the 68k family. It might be that gcc could be convinced to
emit usable code, e.g. by telling it that you want 68010 code. But the
few articles I found on the net (searching for 'gcc 68332' and the
like) didn't make it sound as though it would be as easy as that.

I also don't know for sure that the PowerPC microcontrollers have
exactly the same programming model as the PowerPC desktops; I've just
been optimistically assuming that they do.

Does anyone have more information about this?

(Also, does anyone know anything about the field of view of the Game
Boy or other cheap cameras? I get the impression that I'd be happier
with a wider field of view, even at the expense of resolution. Are
there any cheap cameras with wide angle vision? Or is it possible to
hack something up to widen the field? Has anyone tried getting one of
those lenses used to peer through your front doors to see whether you
want to let someone in, and gluing it to the front of the Game Boy
camera?:-)

-- 
William Harold Newman <william.newman at airmail.net>
software consultant
PGP key fingerprint 85 CE 1C BA 79 8D 51 8C  B9 25 FB EE E0 C3 E5 7C


More information about the DPRG mailing list