Hi,
I am wondering if it would be possible to interface with an rs-232 (serial bus) with an arduino. I have not purchased one but I am investigating using it on a student project to log data from a formula style racecar. The Engine control unit we have is interfaced with using rs-232 and I would like to know if this would be possible with the arduino.
Yes you are half way there already, pins 0 & 1 carry the serial data, all you need too do is to add the voltage translation and logic inversion. There are lots of chips that will do this. I use a MAX202 but see what you can get. Also as pins 0 & 1 go to the USB as well you can use the "new software serial" library to make serial come out on any other pin.
Well the first Arduino clone I bought used RS-232 rather then usb. I still use it a lot as my PC has serial ports as well as usb ports. It was an easy kit to assemble if you have any soldering experiance at all.
http://www.nkcelectronics.com/freeduino-serial-v20-board-kit-arduino-diecimila-compatib20.html
Some other inversion ideas:
http://www.scienceprog.com/alternatives-of-max232-in-low-budget-projects/