GM ALDL interface

[Frederic Breitwieser]

>I don't know, I though a single $.01 transistor was about as elegant as you
>could get. The opto is overkill. Powering the led might be a problem,
>although some lpt lines could be used. But remember that CE data (D) is
>inverted from serial data (E/M). That will need accounting for in the
>interface or the code (preferred).

First, I'd love a copy of your code :)

Yes, an Opto could be overkill, but it ensures 100% isolation.  Driving the
LED is not a problem, since the same output line drives an idiot light on
the dashboard (at least my ECM does), and you are correct, its inverted,
however my 1-transister circuit I sent to Sean (and the list - which I see
came out as garbage) basically is a buffer - what comes in, goes out.


Frederic Breitwieser
Homebrew Automotive Mailing List
Bridgeport, CT 06606
http://www.geocities.com/MotorCity/Downs/4605/index.html
(Portable Webserver Link Address)

1989 AG Hummer 4-Door
1993 Supercharged Lincoln Continental
2000 Mid-Engine Sports Car <smile>

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