[svlug] Linux in a Submarine

[Rick Kwan]

Chris Miller wrote:
> On 12/21/06, Daniel Gimpelevich 
> <daniel at gimpelevich.san-francisco.ca.us> wrote:
>> On Thu, 21 Dec 2006 13:44:36 -0800, Chris Miller wrote:
>>> Right now it has a little 600MHz chip in it that was ripped out of a
>>> PDA/Mobile type thingymajigger (I'm just a programmer - don't ask me!)
>>> Right now it runs Windows Embedded. However, Windows doesn't have
>>> hardly any multithreading support (problematic for real-time
>>> computational tasks) and we want to move to Linux. The problem is
>>> that some of the drivers for the hydrophones and motors we use don't
>>> have Linux drivers.
>> Which 600MHz chip? How are the hydrophones and motors connected? Which
>> USB->Serial connector?
> It's an x86 compatible chip (I don't know who made it). I know that
> from talking to someone much more acquainted with the hardware than I
> am that it uses some odd combo of USB and Serial devices. I'll have
> to get back to you with more information though because the hardware
> guy hasn't gotten me the exact list. I just wanted to know what other
> people thought and what their suggestions where.
I'm not good enough of a device programmer to give you a decent opinion
about reverse-engineering or otherwise attempting to program from a spec
sheet.  But I gotta tell you this is very intriguing.

I saw some handiwork of an Amador Valley team back in 2002, built for an
AUVSI underwater competition.  (http://www.auvsi.org; I believe this is the
competition that Eric Raymond talks about when he compares Linux in a 
submarine
to Windows NT in the USS Yorktown.)  Very neat stuff, and big shoes to fill.
At the time, the one I saw was a Pentium III in a PC104 stack running Linux;
I suspect that stuff is long gone.

Since seeing the Amador Valley submarine (which may have been Barracuda II),
I discovered Gumstix (http://www.gumstix.com), courtesy of SVLUG.  They are
heavily entrenched in robotics.  They use 200 and 400MHz Intel XScale
processors, and have a general purpose I/O "robostix" board to connect to
lots of odd devices.  Now, you might decide that you need Pentium power to
handle the real-time data reduction.  But their user group site
(http://www.gumstix.org) has lots of FAQs on lots of subjects, including 
one
on "Setting up USBnet".  The information may apply to x86 as well.

As for other readers here, if you're looking to see how a high school team
can sink its teeth into robotics, I'd look at this team or one of the teams
in the high school-oriented FIRST Robotics competition.  A high school team
entering the AUVSI competition is really rare.


--Rick Kwan