Reading ALDL 8192 stream from '165

[Craig Moates]

Making progress am I?

For my case, things are starting to appear better for reading the 165 ALDL
data stream. Depending on whether the key is on, engine running, etc. I get
different-looking data at 160 baud communications speed through the MAX232
with 10kohm across the A-B. Some of the streams are shown below, and any
help deciphering would be appreciated, even a referral.

The next question is, how do I get the ECM to send the 8192 data stream -
what commands to send, when to send them, how to do so, etcetera. I hate to
be all questions and no answers at this point, but once I get this working,
I'll post a summary of the results and upload the source & such for the
Q-Basic data logging/reading program I'm making. It's a modest effort in
comparison to some of the things I've heard described here, but it's a good
short-term goal. I'd really like to give something back.

-Craig

Sampling of the data as it appears at simple 160 baud serial byte-reading
(some with engine off, some running):


00-FF-5E-ED-C1-D2-FF-F7-5D-F5-FF-DC-FE-
00-FF-5E-ED-FE-D2-FF-F7-5D-F5-FF-DC-FE-
00-FF-5E-ED-FE-D2-FF-F7-5D-F5-FF-DC-FE-
00-FF-5E-ED-FE-D2-FF-F7-5D-F5-FF-DC-FE-

00-FF-5E-ED-C1-D2-E6-F7-FF-97-FD-87-DF-7D-FE-C8-
00-FB-5E-2B-C1-FC-E9-D6-F7-5D-F5-0E-CF-9D-FC-BF-
00-FB-5E-0B-C1-F6-EE-D6-F7-5D-F5-0E-F7-CD-FE-DE-
00-FB-5E-73-C1-EF-DC-D6-F7-FF-97-FD-87-17-4D-FF-CD-
00-FB-5E-33-C1-E7-DC-D6-F7-FF-97-FD-87-EB-B9-FD-ED-
00-FF-5E-33-C1-FB-DC-D6-F7-5D-F5-0E-B3-39-C3-

00-FB-5E-D3-C1-EB-DC-E6-F7-5D-F5-0E-A3-D9-FE-93-
00-FB-5E-D3-C1-EB-DC-F6-F7-5D-F5-0E-CD-D9-FE-CB-
00-FB-5E-D3-C1-F3-DC-F6-F7-5D-F5-0E-25-D9-FE-B3-
00-FB-5E-D3-C1-F3-DC-D6-F7-5D-F5-0E-59-D9-FE-AB-

00-FB-5E-53-CE-F3-DC-D6-F7-FF-97-FD-87-97-59-FE-BB-
00-FB-5E-53-CE-EB-DC-D6-F7-FF-97-FD-87-DB-59-FE-EB-

00-FB-5E-63-FA-F3-DC-DA-F7-5D-F5-0E-F7-09-FE-EB-
00-FF-5E-63-FA-F3-DC-D6-F7-5D-F5-0E-A7-09-FE-9B-

00-FB-5E-63-EA-F3-D2-C6-F7-FF-97-FD-87-99-09-FE-FB-
00-FB-5E-63-EA-E3-D2-FA-F7-FF-97-FD-87-19-09-FE-C7-

00-FB-5E-63-F4-ED-D2-C6-F7-5D-F5-0E-41-09-FE-F7-
00-FB-5E-63-D4-F5-DC-C6-F7-5D-F5-0E-1F-09-FE-CF-

00-FB-5E-E3-C4-E5-D2-C9-F7-6D-F5-0E-CD-49-8F-
00-FB-5E-E3-C4-ED-DC-D9-F7-6D-F5-0E-D5-49-D7-

00-FF-5E-ED-AF-D2-F6-F7-55-F1-40-3F-CF-FC-
00-FF-5E-ED-AF-D2-F6-F7-55-F1-40-3F-CF-FC-

00-FB-5E-1B-CF-F9-3C-CC-FF-F7-FC-65-F5-86-FF-7B-FF-8F-
00-FB-5E-5B-CF-FB-3C-E4-FE-F7-FC-65-F5-86-FF-7B-FF-AF-

00-FF-5E-ED-B7-32-EA-F7-45-F5-1A-7F-DC-FE-9F-
00-FF-5E-ED-B7-32-EA-F7-45-F5-1A-7F-DC-FE-9F-

00-FF-5E-ED-F7-D2-FF-F7-45-F5-FF-DC-FE-
00-FF-5E-ED-F7-D2-FF-F7-79-F5-FF-DC-FE-

-----Original Message-----
From: Ludis Langens <ludis at cruzers.com>
To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
Date: Wednesday, October 13, 1999 6:11 PM
Subject: Re: Reading ALDL 8192 stream from '165


>Craig Moates wrote:
>>
>> I've done exactly no serial I/O programming to this point, so I could be
>> missing the boat here. I do get values, but very limited (like FE, 00,
FC,
>> and that's about it). These repeat pretty regularly. I've used 'PCMComm'
>> with similar levels of result. What's next? How do I tell this ECM to
talk
>> to me, and what are these values I am seeing, assuming that they are
really
>> from the ECM? When I disconnect it, or the power supply, everything goes
to
>> zero.
>
>Isn't the '165 one of the few applications that start out in 160 baud
>mode, and only switch to 8192 mode after receiving a specific command?
>(The FE, FC, and 00 match what you'd get with a 160/8192 baud rate
mismatch.)
>
>--
>Ludis Langens                               ludis (at) cruzers (dot) com
>Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/
>
>