Software On ELM Street - OBD2 Software Development

[Charlescrown]

The diagnostic plug is under the dash on the right hand side of the steering column. Good luck.

[Tazzi]

Yeah will have to try it out on the i30 when the cable rocks up.

I tinkered with some other software, and it didnt see the response unless I added the carriage return.. so now Im really stumped!. Unless that software reads byte by byte until it finds carriage return,newline or >.

Ill try adding a few different read methods.
Read 1 will be the normal read we have now, relying on the carriage return to pick up the message.
Read 2 will rely on there being a newline present..(have to keep linefeed enabled for this)
Read 3 will rely on the elm idle status. As soon as it receives that.. it must have completed the message.
Read4, will simply loop through and continue trying to read byte by byte until cancelled.

Annnd, cant think of any other ways the device may output so will update with the above for the engine section.. and see how we go from there.

[Charlescrown]

Well Tazzi you have me lost. You obviously have a good command of computer language but to me it's all gobbly gook. I am a mechanic by trade but spent 30 years in training motor mechanics for TAFE NSW and have a good knowledge of vehicle data and scan tools but I take my hat off to you. Let me know by updates whats happening.

[Tazzi]

Ah its not as bad as you think charles, the basic understanding of the OBD2 protocol isnt so bad.. I learnt everything from the documents in my first post! And been just learning as I go.
As for the programming. Yeah, thats a "learn over time" type of thing, but theres so many tutorials on absolutely everything.. a simple google will give a great examples to base whatever your after off.

[Jayme]

Well, I was busting to try this on my elm, but I couldnt as my bluetooth module on mine died..... had a brainwave today and decided to hook up a TTL usb converter up that I had laying around. found the elm chip pinout and hooked it up, lo and behold, it worked.

elm327-1.JPG (67.16 KiB) Viewed 5947 times

elm327-2.JPG (46.47 KiB) Viewed 5947 times

also gave me a chance to try out VN5000's adx that he made years ago... I cant rememeber where I downloaded it so here it is

GM AND SAE V2.20.adx

(208.08 KiB) Downloaded 392 times

this adx works fine for me on my elm...

this is the ADX that gave me the idea to make my AVT ADX... but the avt was a lot easier than this one coz you dont need to do any ascii conversion or anything.

[delcowizzid]

nice good to see it works i have to do some work round the corner from the VT tomorrow ill test i out too

[Charlescrown]

Hey Delcowizzid hows the car after the wheel catastrophe?
You guys are sending me head into a spin. I need to spend a lot more time trying to understand ECU data etc but I am slowly learning. I was just wondering why some ELM units link at a much lower speed than mine? Also with quiet a few OBD2 protocols will this end up generic or specific? Does it matter in the programming? I assume it does. I know the output pins are different but is the data the same?
Must be bloody cold in Woodburn -39?

[VX L67 Getrag]

Finally Got around to testing it & new the settings mine worked at & have to say looking good!

NICE WORK!!!

[Jayme]

Hey Delcowizzid hows the car after the wheel catastrophe?
You guys are sending me head into a spin. I need to spend a lot more time trying to understand ECU data etc but I am slowly learning. I was just wondering why some ELM units link at a much lower speed than mine? Also with quiet a few OBD2 protocols will this end up generic or specific? Does it matter in the programming? I assume it does. I know the output pins are different but is the data the same?
Must be bloody cold in Woodburn -39?

haha yeah thats coz my ls1 pcm is sitting on my bench and its only got power, earth, and obd2 hooked up to it! as for the strange differences between the elms, I woudl hazard a guess its the differences between chinese clones and the real deal, and the small differences and bugfixes between the various versions.

as for being generic or vehicle specific, for OBD2, each peice of sensor data from the pcm is called a "PID" and there are 2 types of PID's SAE PID's which are required for any car to meed the obd2 specification, and there are manufacturer specific PID's. the 2 groups of manufacturer specific PID's that I know of are "GM Enhanced" and Ford somethingerather. so all the SAE obd stuff should work on any car

[Charlescrown]

OK now I starting to grasp it. I new about the PID's and the two groups with the second being vehicle specific. Their the harder ones to detect without manufacturer software or software that contains them. I was not sure about the different protocols and how they are read. I know what I am using now rolls through a list before setting the scantool to one.