A challenge for "aldl data stream decoders"

[Paul Blackmore]

This is my first post to this list so if this hotmail account screws
something up, let me know.

Before I start, thanks to Peter Gargano and Carsten Meyer for
the information they have provided :)

I've been following this list almost since it began but have only just found 
time to get stuck into hacking my ECM for real :P

I am trying to decode an 8192 baud aldl data stream... (isn't everyone?) for 
an Aussie V8 P4 (I think).

I connected my laptop to the aldl data stream, went for a drive
and logged the data described an excel spread sheet: aldl_8192.zip at
http://www.users.bigpond.com/paul_blackmore/CProgramming.htm

BTW the V8 that is home the the ECU is at:
http://www.users.bigpond.com/paul_blackmore/VSCommodore.htm

I have "named" some values that I think I can identify but
I may be wrong. If anyone would like to have a look at the
spreadsheet and give me their opinion on what any of the
byte streams (B1 through B56) might represent that would
be great :).

I have graphed the data in the spreadsheet in different
worksheets to make it a bit easier to visualise.

I have read just about every aldl data stream reference document
that I can find but none seem to match the data I am seeing.

The data in the spreadsheet is exactly the same as output from
the aldl connector, I have not scaled any of the values.
So scaling info would be good as well. (Scaling seems to be
the same as most other documents I have seen on the web).

Once I get the stream worked out, I'll publish it along woth the
software tools that I have developed to help me hack.

I send this request:
f4 56 01 b5

$f4: Command header
$56: Message length $56-$56=0  == 0(decimal)
$01: Request aldl data stream
$b5: Checksum

I get this type of response (just one sample of many, see spreadsheet for 
comprehensive display of sampled data)
f4 8e 01 0e b6 03 0d 35 6f 89 72 0c 00 fd 22 51 00 1a 01 00 7e 00 80 75 14 
8d 02 8e 00 02 00 00 00 66 00 43 00 07 2e 07 00 00 00 00 00 00 00 00 00 00 
00 20 00 71 00 00 00 00 00 57
   Byte:  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16 17 18 19 20 21 22 
23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 
48 49 50 51 52 53 54 55 56 Checksum

$f4: Command header
$8e: Message length8e-$56=$38 == 56(decimal)
$01: Request aldl data stream
$b5: Checksum

Thanks for your help :)
Paul Blackmore

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