Vitaliy wrote regarding 'Re: [EE]: ALDL information?' on Wed, Dec 14 at 12:28:
> "Danny Sauer" wrote:
> >Even disregarding cost, why would I *not* want to learn more about how
> >my car works, and have the satisfaction of building my own tool?
> >Because it'd be easier to pay a 4-digit price for something that still
> >won't operated exactly the way I want?  Because "computers are scary"?
> 
> The problem is, you can't get far on pure enthusiasm. At some point, your 
> rational side will kick in and ask: why in the heck am I doing it this way?

I bought a car a few years back that would benefit from a new engine.
Then I bought a shop crane to pull the engine so I could install the
new one.  I bought a shop crane because it made more sense, and an
as-purchased device would do everything I wanted.  I built the engine
myself because it didn't make sense to pay someone to do something I
can do myself, and because if I do it myself, I know it'll be done the
way I want.  I suppose the "rational" thing to do would have been to
give up, call a tow truck, sell the car as scrap, and buy a new car?
After all, most towns have new car dealerships, and it's much easier
to buy a new car than to build one.  New cars don't generally do
everything I want, though, so I'd be forced to settle.  I don't like
to settle when it's within my reach to get exactly what I want.

Same deal.  I can't afford to buy a tool that does most of what I
want, and I'm honestly not sure that a tool exists at all which will
do everything I want.  So I've gotta figure out how to make that tool
myself if I want that tool.  I'm close now...

> "ALDL-ready" laptop won't cost you more than $100. You don't need anything 
> above a 486, unless you plan to play DVDs and code in VC#. ALDL-RS232 
> converter costs less than $10 in parts, and takes roughly 20 minutes to 
> build. Software you can write yourself -- weren't you eager to program a 
> PIC to do the same thing?

Yes.  Except, an ALDL-ready PIC is already sitting on my desk (blame
Olin for getting me interested in that chip), it'll require the exact
same information to program a PIC as it would a laptop, the PIC will
be closer to the correct baud rate (a PC just gets "close enough"),
and I can combine the PIC with a display I already have to create a
tool which will fit in the car more easily without requiring all of
the baggage a laptop will bring.

Besides, if I was gonna use a laptop, why would I write my own
software when I could get pre-written software that does what I want?
That'd be silly. ;)

> [snip]
> >3) figuring out how to diagnose it
> >myself (I can already *fix* it myself once I know the problem).  I'd
> >expect anyone reading this list to understand the draw to option 3.
> >Those few who don't, probably never will.
> 
> I rarely understand people who want to do it "the hard way", unless the 
> purpose is purely educational. Taken to the extreme, the logic becomes 
> ridiculous.

Find me a device I can plug into my ALDL port which will read the
error codes on my '95 LT1 Caprice, erase stored codes, and display
*all* of the diagnostic data available in a configurable way - like by
letting me display about 8 values of my choosing simultaneously.  Oh,
and it should be small enough that I can mount it in the ashtray.

That tool does not exist.  Even without the portable aspect, we're
looking at more than the car's purchase price.  It has nothing to do
with "the hard way" and everything to do with "making things work the
way I want them to work".  Well, not everything - I also have never
done something exactly like this, and I'd like to learn how.
Learning's important. :)  I know other enthusiasts who would be
interested in the same device, for that matter, but sharing knowledge
is a ways off.

> Danny also wrote:
> >Well, yeah, but I'd rather not lug my desktop computer out to the car,
> 
> Ever heard of CarPCs? :) Find an old desktop, put it in the trunk, use it 
> to play MP3s and read ALDL.

Yup, about 7 years ago, when I mounted a Cyrix-based PC in my '80
Caprice and then failed to document it very well:
http://www.dannysauer.com/cdproject/ (done before the "first" guy who
put a PC in his Miata got a lot of press, BTW, though he did more
"cool" stuff).  The remains of that project are the backup if I can't
get the PIC to work well in this plan.  However, after the experience
of setting up a PC in the car, I've come to realize that a PIC would
make a lot more sense.  For playing mp3s, I've bought the models from
Kenwood and Alpine which do that better and easier than I could.  The
price is low enough on those things now that I'd be hard-pressed to
justify building my own again, even though it was somewhat neat to
open the glovebox to the back panel of a full PC. :)

> >and I'd also rather not install Windows on any computer. :)
> 
> At first I did not realize this was a religious issue. But then again, it's 
> irrelevant whether you're running Unix or MacOS -- if you write the 
> software.

It's not a religious issue.  A laptop would be a general-use device
for me.  Windows is not of general use for me.  Other people are free
to use Windows, and that's great if it's the right tool for their job.
Windows is *not* the right tool for the bulk of things I'd use a
laptop for, though,with the single exception or running LT1-edit
and/or Tunercat.  Even those should work alright under Wine or VMWare.
Just FYI, in case I come off as a Linux zealot or something.  It just
works better for me.

> Great idea! Buy a small LCD panel, hook it up to the PC and display 
> information on virtual gauges. Have a button that will switch between the 
> gauges, and read trouble codes.

I wonder if I could do this with the PIC I already have and the VFD w/
keypad interface and bargraph capability I already have? ;)

> >Someday I should just buy a laptop...
> 
> Yes, you should. :-) They are not as expensive as you think.

Ok, technically I already have one.  But it's routing my home network
traffic, and I can't really take my domains off-line every time I want
to go diagnose car troubles.  It'll be used when I get to the point
where I'm actually tuning the engine to compensate for the performance
modifications planned.  I should have a desktop-based router built by
that time.  For now, I've gotta choose whether I spend my timebuilding
a neat tool, or replacing a functional router.  I'd prefer the
challenge of building a neat tool.

--Danny
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