Ignition Pulse extraction from 808 over Aldl

[nickcasio]

Working on a project for a friend, they working on a software pack for tuning (theoretical Dyno Tuning), at the moment the software is aimed at Holden commodores, The software is a demo mode currently and is using a simply inductive pickup around a spark plug lead to get timing information.
My intention is to extract the timing information as well as other parameters over aldl or obd depending on the variation of Delco computer. I am an engineering and under standing serial rs232 interfacing as well as serial data manipulation. The question i pose to the forum is can anyone help me out with talking to the delco in a program such as hyper terminal! to get basic ignition timing data, such as timing advance and ignition pulse.

Kind Regards
Nick Owen

[festy]

Have a read of the ALDL basics thread - https://pcmhacking.net/forums/viewtopic.php?f=10&t=219
I've just written some code to interface to an 808 to log that kind of data, once you understand the message structure ect it's pretty straight forward.
But Hyperterminal won't be much use for it, it's a binary protocol.

[VL400]

From a VN/VP 808 the 160baud ALDL will mean spark advance update is really slow (~1Hz), so pretty useless unless you equip it with a VR/VS manual memcal (or 12P) and use a high speed comms board. On VR and later 8192 ALDL can get up to around 40Hz with a reduced message size. Its a bi-directional half duplex link so can request things from the ECU and have it return what you want.

Download the 12P package and have a look at the ADX files in TunerPro. It shows the message that is sent, the return frame details and what each byte/bit contains. The message 6 ADX logs faster due to the smaller return message size.

[nickcasio]

Also planning on writing code for the faster communications standard OBD I and II, I am planning on using Matlab extrapolate the data!