Hi! and welcome to the forum! This topic is in the wrong place, so it will be moved to the OBD2 subforum.
http://www.scantool.net/dev-tools/stn11xx/stn1110.html (ELM327 compatible, but WAY more features, and much higher quality), or buy one of these: http://www.scantool.net/dev-tools/mo...roobd-200.html Which handles all the extra hardware required to connect to OBD2 signaling.
What are you trying to do? Perhaps if you gave us an idea what your end goal was, we could better assist you?