Re: [NTLK] Question about using a newton MP 2100 as a ODBII scan tool

At 02:47 AM 11/15/2008, you wrote:
> I know it sounds far fetched, but would it be possable to somehow
> use the newton as a ODBII Car diagnostic tool/scanner. i seen some
> open sourced projects but couls one be ported to work on the newton
> (with the proper adapter).

Not at all far fetched. If you look at something like the ElmScan 5
(from various places on the net) it converts the various OBD-II
interfaces (at least 3) to a serial connection.

The ElmScan device is based on a chip from Elm Electronics of
Toronto, Canada. Elm takes Microchip PIC chips and programs them to
do all sorts of wild and wonderful things. The ones that seem to have
taken hold are their various OBD to serial converter chips. Along
with the chips, Elm provides example schematics to give an idea as to
how the chip should be wired up. Various companies have implemented
the example circuit and sell it as a product.

The conversation between the Newton/PC/controller and the OBD bus is
reasonably simple. Elm provides a command interpreter where you send
"AT" commands to configure the Elm chip (just like a modem, anybody
remember modems?) and data commands that are converted to the proper
format and dropped onto the OBD bus, the Elm chip then sends back
reply data. AT commands talk to the chip - "ATE0" turns off command
echo. Other commands talk to the OBD bus - "010C" is the command to
get the RPM data, a reply looks like "41 0C 5A FB". Commands are
ASCII coded hexadecimal numbers.

So, the physical hookup would be something like a 2100 with a dongle
hooked to a DIN-9 to serial cable, connected to the ElmScan 5,
plugged into the OBD plug (which is at most 1 meter from your driver's seat).

The software would be quite simple and could be derived from the
serial endpoint example code. I don't expect that there is any reason
why this wouldn't work on ANY Newton, Notepad through 2100.

See "OBD-II PIDs" in Wikipedia for a list of the information that can
be extracted. There are manufacturer independent data items (PIDs)
that are common across all OBD-II computers and manufacturer specific
PIDs that are specific to a manufacturer or model. Note: Suzuki and
Volvo don't publish their manufacturer specific codes.

Andrei

>Frank

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Received on Sat Nov 15 16:55:08 2008