Thread: any interest for a cheap obd2 reader?

hmn..think you could post the schematics?

http://www.elmelectronics.com/DSheets/ELM323DS.pdf

The diagram is there

Heres a full OBD2 project from Elektuur/Elektor magazine :

Rename all the 3 files back to RAR and unpack...I cant post more than 200KB.

Use the document for reference or whatever...just dont blame me when things goes wrong.





EDIT : Look like some didnt get what I meant by rename back to RAR...What I meant is remove all the .ZIP extension so you are left with .RAR extension. Use the software WINRAR to unpack all 3 files. There should be a PDF file in there

the board is the same as ricky327 posted, i just made mine with a 9 pin instead of a 25 pin serial port, i am also going to be adding a turn on relay so that the unit is only powered on when the computer or car is on. There is alot of software out there, www.scantool.net is one. I am also making my own software for the interface that will be strictly a virtual dashboard. far as capabilities, this will read all the suported information that your car can provide to it, check engine codes, and clear them. I might do a usb one also.

Originally Posted by arkadiyp

I've looked into ELM products a while back, and unless they've improved them, the product is extremely limited, and IMHO its cheaper to build one of these considering they don't use any specialized parts, and many people here will most likely have everything needed.

In addition ISO standard does not really require ELM interface, there is a project on sourceforge.net that has software solution. Reason for that is that ISO interface can be understood by RS232 without major modifications to the electrical part.

what is the name of the project?

just go to www.scantool.net all the circuit schematics to build their tool ( ELM323 based ) are there - did the same, cost me under £15 in parts....
James

I'm interested! But my car is OBDII-CAN interface. I tried to source a chip that will support the CAN interface, but no luck so far. Maybe you stumbled on one somewhere? Because if so, i would be all over it

There is one difference between boards out there and that is, some have buffers built in on the interface, so if 'anything' goes wrong, it won't destroy the cars computer.

Just something to think about ...

good point...you might be able to use the 74367 HEX BUFFER. its what i saw in a parallel port interface schematic. i'm not too sure aobut my electronics knowledge though...

There are a couple of open source OBD-II software projects available on sourceforge.com. Most of these run on a PC. There are also some inexpensive Palm OS based OBD-II tools available at obd-technologies.com