Elanscan cable

[peter123]

I have finally got my elan project car in the garage,so the job of sorting it out can start.So i could really do with the Elanscan cable to see how things are with the engine,I have tried emailing there's only on f in Geof Smith regarding purchasing one but not had a reply,so does anyone know if he still does them or anywhere else i could get one from.?

[Rambo]

Geoff may well be out of the country at the moment. Probably otherwise engaged on his sunbed in Sangrialand

[peter123]

Cheers Rambo,hopefully he is still doing them as i can't find anyone else that does them.

[Giniw]

It is actually rather easy to do a simple version as long as you don't mind using a direct connexion — Geoff's version is optically isolated.
http://www.astb91.dsl.pipex.com/

[GeoffSmith]

Sorry Peter. MacAffro is correct but I am back in the UK on the 19th for a couple of weeks. I'll pick up your e-mail when I get back.

[peter123]

Thanks Geoff.

[peter123]

Thanks for the link Giniw,had a look at it,but i will wait for one from Geoff,electronics arn't something i am that keen on,i'm ok with a soldering iron,but understanding how them little things you are soldering work is just some sort of black magic.

[Giniw]

Well actually there is nothing to understand if you choose to go for the usb/serial adapter (aka "Easy home build solution"). There are only 2 wires to solder to the board. But again it's less safe than the optically isolated version of Geoff since there is a physical connexion between the board and the ECU.
Choice is all yours

[peter123]

Didn't realise you could buy the usb,serial board already made up,so i see it wouldn't be to hard to make your own,but as you say Geoffs are optically isolated so less chance of frying the ECU,so on this occasion i will wait for one from Geoff.
Thank you for the informative input Giniw.

[GeoffSmith]

That design drives the output high which could potentially cause the ECU output to blow. There have been a couple of ECUs that have stopped communicating and this could be the reason. Mine only drive low as the design intended.

[Giniw]

Well, would you mind to elaborate a little? I'm using an arduino usb/serial adapter so far so ... (of course the arduino output is 5v, not 12v)
(https://en.wikipedia.org/wiki/ALDL#Data_Stream)

edit: Do you speak of the way each bit is encoded (high to low transitions, etc?)
http://wbo2.com/~techedge.com.au/vehicl ... htm#serial ?

[GeoffSmith]

ALDL is half duplex: The ECU output is a 10 kohm resistor to +5V with a switched transistor to 0V. The interface must also have a switched transistor to 0V only. The maximum current that can flow in the ECU output transistor is 5V/10k ~ ½mA.

If the interface is switched via a transistor to 5V in the off state, then when the ECU starts to respond, the maximum current in the ECU transistor is determined by the output capability of the interface and could be 100s of milliamps. You would be advised to put a diode in series (Anode to the interface output and cathode to the ECU). The interface low output will increase by ~0.7V but should still be recognised as a low by the ECU.

[Giniw]

Thank you, I think I understand — I am more on the software side ^^

[Giniw]

Geoff, I think you made a little typo about the diode wiring, didn't you?
Shouldn't it be soldered the other way round? (ie the anode to the ECU and the cathode to the computer TX interface?)
There seems to be a general consensus about that (https://forum.lotuselancentral.com/view ... 14#p332414), even including an earlier post of yourself (viewtopic.php?p=152753#p152753), so ... ^^