interface to a pc

ariesdude · Post by **ariesdude** » August 30th, 2005, 4:11 pm

Hi, anyone know what would be involved (hardware/software) in getting the ECU and possibly the (auto) transmission controller interfaced to a PC laptop running windows or something. I am thinking of wiring up a laptop in my mx-3 and use it to monitor the engine and transmission during normal day-to-day driving. Any info is greatly appreciated. Thanks.

Post by **Custommx3** » August 30th, 2005, 4:25 pm

http://www.megasquirt.info

ariesdude · Post by **ariesdude** » August 30th, 2005, 5:19 pm

Hey thanks for the reply - i looked into megasquirt before and it is promising - but i want something to just monitor the parameters and not control anything - definitely not fuel injection - i say that because i beleive if i start screwing with things like that the engine might just blow up one day or something. So i just want to monitor whatever data the ecu is sending out and maybe build a custom software to display a second set of gauges on the computer screen - i am also thinking about a custom mpg gauge by monitoring ecu outputs.
Does anyone know what protocol is used by a 94 mx-3 1.6L 4 cyl DOHC ecu - OBD1 or 2 (ISO or KWP or J1850) or something else altogether. Thanks.

Post by **Custommx3** » August 30th, 2005, 5:23 pm

you have ODBI

Unless u knew the codes and had some type of data aquisition card, you cant.

Ive built a car PC and I wanted the same thing, Im having to goto Megasquirt.

ariesdude · Post by **ariesdude** » August 31st, 2005, 3:31 pm

I found this link - http://cable.invisibill.net/
it has info about how to make a custom cable to read data from ecm into a computer - we would still need some software like datamaster or freescan or something - if we could get some data sheets to make sense of the data that flows in we might be able to write our own software - but this is the first step i guess

ariesdude · Post by **ariesdude** » August 31st, 2005, 3:32 pm

These guys have readymade cables for obd1
http://www.aldlcable.com/

Post by **Custommx3** » August 31st, 2005, 5:33 pm

There are basically 3 things you need to record diagnostic data from a GM based On Board Diagnostic 1 ( OBD1 ) system on your 1982 - 1995 era car.

brakecrasher · Post by **brakecrasher** » February 26th, 2006, 5:42 pm

Sorry guys, but i don't understand exactly.
If i decide to install megasquirt i must connect it
to the ecu or it works without it?

Thanks in advance

Post by **Custommx3** » February 26th, 2006, 7:02 pm

Its a standalone unit. Just use your ECU for things such as dash cluster.

FlyVFR · Post by **FlyVFR** » February 26th, 2006, 9:12 pm

Sounds like a good project. There are a few custom ways to gather info. The easiest way is to use the ECU data port coupled to the PC serial port. The other method would be to interface all sensors directly and develop a data aquisition circuit which can deliver USB, Parallel or serial data to the PC. The software can be custom tailored to the ap.

ariesdude · Post by **ariesdude** » February 26th, 2006, 9:24 pm

i tried looking for the data port in ecu - cant find it ....
looks like pre 96 mx-3s didnt come with a data port.

brakecrasher · Post by **brakecrasher** » February 27th, 2006, 5:39 am

Does Anyone know where i can find a usb interface to conect
pc to the ecu or diagnostig plug?

Post by **Custommx3** » February 27th, 2006, 9:38 am

You cant. OBDII wasnt introduced until 96.

FlyVFR · Post by **FlyVFR** » February 27th, 2006, 11:06 am

brakecrasher wrote:Does Anyone know where i can find a usb interface to conect pc to the ecu or diagnostig plug?

I don't think it exists. As I mentioned, it is possible to build a data aquisition circuit and choice of PC interface.

BTW- Bella pagina del Internet!

brakecrasher · Post by **brakecrasher** » February 27th, 2006, 3:12 pm

OBD2 in italy come in 1994.

But i have a OBD1 92 mx3,
someone can help me?