ALDL protocol

[al]

Hey guys (Alan esp.),

does anyone have the aldl spec ?

I'm messing around with a little project at the moment; trying to interface this with my Elan. I've got some prototype code at the moment which will parse a response payload that elanscan gets back from the ECU, but I can't seem to get the ECU to respond to my requests (do I need to send some command to put it into a mode where it will respond to the 0xf45601b5 request ? ) :/

Can anyone shed some light ?

BTW Alan, I'd really like to have this be able to save out .ecu files so that proper analysis/comparisons can be done back home on the desktop with elanscan; any chance of getting the format of these files from you ?

Cheers,
Al.

[ailwyn]

Al,

Are you transmitting at the correct baud? 8192 is the correct ALDL baud, but on the PC the closest it can get to is 8228.5xxx (115,200/14), which (apparently) is close enough not to cause problems.

I've asked Alan in the past about the file layout, and he doesn't have a spec, he just saves the object/structure using a pre-defined routine. Having had a quick poke around I have found the locations of some of the ES data, but never spent any time trying to reverse engineer it all.

Hope that helps

Ailwyn

[GeoffSmith]

The ALDL interface is half duplex. Electrically, when writing, it appears as a 10kohm pull up resistor to 5V. Some people have got away with driving directly from an interface output but I always use an open collector buffer. If you are driving directly, then make sure you return the output high and that you're not driving it with any significant impedance - you could use a small signal diode (anode to ECU and cathode to interface). The return data (63 bytes IIRC) is merely spat back from the ECU on completion of the command word.

I have reverse engineered the data and can read it into an Excel spreadsheet. I'll dig out my notes for you.

Roll on Donington....... Cor, look at the bits on that!

[al]

Nice one, cheers lads !

Managed to coax 8192baud out of the serial adapter with a bit of persuasion, got a first cut up and running talking to the ECU today.

I used the .ini file from ElanScan to generate the codec, it turns out that ElanScan derived quite a few of its variables (all of the ones in the .ini file where size=0) from data returned from the ECU, if you've got any ideas about what those calculations might be I'd be keen to hear them !

[GeoffSmith]

I'm sure I've got them somewhere.

[Veikra]

Hello people,

Im trying to get elanscan running on xp , but im wondering how to set my comm port to a non stardard baud rate of 8192. Im using an usb to serial adapter, but also tried with a pc with srtraight serial even thoo i know it wouldnt work unless i get the right baud rate.

Can anyone help me figure it out?

[ailwyn]

Elanscan itself sets the correct baud rate.

Just set your serial port to 115,200 8N1 and the software should take care of the rest.

When using a USB to Serial converter, there are one's that are known to work, and others that are known to have problems (it depends on the chip that they use).

Ailwyn

[Veikra]

Well i got the same error message with a serial port pc and with laptop and adaptor, so for now my problem is not yet at the usb serial cable. That might come later. I will try the port setting you gave me when i get a chance to try(hopefully soon).

Thank a lot

[Veikra]

Ok,

Seems like my adaptor isnt working, so I designed a usb one based on the ftdi chip and now waiting for the printed board to arrive (sponsorship )

Ill let you know when i get them.

[al]

You could've ordered a known working USB<>ALDL board from Geoff, comes complete with bizarre plug and optoisolators for a very reasonable price !
Mind you, I didn't either

So Geoffers, how about digging out that spreadsheet with the derived variable calculations ?

[ailwyn]

So Geoffers, how about digging out that spreadsheet with the derived variable calculations ?

And putting it where anyone can have a look

[GeoffSmith]

Sorry Al, it is on my todo list but you know how it is........

So Geoffers, how about digging out that spreadsheet with the derived variable calculations ?

And putting it where anyone can have a look .....

.... as long as Ailwyn's prepared to drop his trousers and bend over.

[al]

hehe ok, there's not really any rush, just thought I'd take the opportunity to make sure you hadn't forgotten

[ailwyn]

.... as long as Ailwyn's prepared to drop his trousers and bend over.

I'm far to generous for that... always a giver, never the taker

[Veikra]

You could've ordered a known working USB<>ALDL board from Geoff, comes complete with bizarre plug and optoisolators for a very reasonable price !
Mind you, I didn't either

I didnt think the usb one was already up for sale, and there seemed to be a huge waiting list on the rs232 already. Plus i did have other board to send, so i slipped it in that batch.

Where is Geoff located? US? England?

[ailwyn]

Where is Geoff located? US? England?

England, although we are trying to get enough donations to buy him a one way ticket to the US/Australia/China take your pick

[Veikra]

Canada ! thats my pick

[GeoffSmith]

I didnt think the usb one was already up for sale, and there seemed to be a huge waiting list on the rs232 already. Plus i did have other board to send, so i slipped it in that batch.

Huh?

>100 satisfied customers.

[Veikra]

I didnt think the usb one was already up for sale, and there seemed to be a huge waiting list on the rs232 already. Plus i did have other board to send, so i slipped it in that batch.

Huh?

>100 satisfied customers.

hmm... hooray for dyslexia ? :p I did browse on the forum, probably saw an older post that made me believe there was still a list going.

what can I say? im new

[GeoffSmith]

Welcome to LEC Imnew.