Hi, sorry for bringing up an old topic, but I started to work on exactly same project. I need some help and I believe I'll be able to contribute later with my results.
First things first - I'm building the cable myself. I will also want to try it with a PC via USB before working further with Arduino.
So as far as I understand - I can skip all the MAX232 part, since I don't need to convert ECU serial signal to RS232 and then back from it to USB, right? I just need to cross-over the Tx/Rx lines, correct?
