New project (using OBD-II to USB cable that uses LM339 and FTDI chips for interface?)

[guill_]

Hello, I'm guille, new member of the forum!

I have started an OBDuino project and I have some questions, maybe someone can help me.

I have a OBD-II to USB cable that uses a LM339 and FTDI chips for the interface. I have been reading in opengauge how to build an interface with another chip and DB9 connectors etc. Is this necessary? Can I use my cable and avoid building the interface?

In case this is posible, I would like to leave the cable connected and, if it's possible, leave the usb plug free to connect the pc when needed, and use extra wiring to connect the arduino.

Thanks for all.

[guill_]

Anybody??

I have been researching but I don't know exactly how to search this things because I don't know what I'm looking for. It seems that the interface I have on my cable can be connected to arduino. The FTDI chip converts USB to RS232, is that right?

Then I don't understand the main function of the interface. It takes the OBDII data and convert it to RS232? To use the VagCom sofware I had to set USB port as a virtual COM port.

Please help me! I can't get Freescale chips to build the interface. The circuit of this interface is very simple, but I don't know anything about ISO/Serial/Usb protocols.