I really want to build a circuit that can be controlled from the PC and that can give input to the PC....can you please tell me about a suitable website, needed equipment and software...is computer programming knowledge needed????
First off, what are you lookgin to control? You can use the parallel/printer port for some simplier control, and serial port if you need to control a lot.
Second of all, you are using it on a computer and you are looking to do it yourself (I'm assuming), so computer programming is a +
A (long) while back I was looking at controling a stepper motor through the parallel port. I just searched for info about programing the parallel port.
Also, I found this link on AVRfreaks and I thought it was quite applicable here.