At the absolute highest level, I want to be able to click a button on my computer and an LED turns on somewhere else. Breaking down the problem, one approach might be to have a server that controls a com port using php and then a client computer might load a webform. Any other feasible methods?
For my idea, I haven't a clue where to start with the php script. Can anyone link me to external libraries I can just download (and not sign up for anything) with good API documentations? Or does php itself provide an API?