When I get back to school on Tuesday, provided that my memory doesn’t fail me as it usually does, I’ll find out what the name is of the boards sitting in the closet of my Microcomputers class.
I’m pretty sure that my professor used an expensive and bulky program called LabView to make a custom interface for them, but I’m sure that they come with a generic interface or can be accessed by a programming language.
I think the big clunky ones we used in Physics were called Data Studio, or something similar.
I don’t recommend those, though, as they only had a handful of inputs and outputs.
Doing a quick google search, I came up with these, which are the kinds of things that you’re after.
measurementcomputing.com/Usb_analog_i-o.html
Really, you just want a connection (DB9, parralel port, USB, etc) on your PC that controls I/O pins.
If your reading sensors, make sure that your device of choice has multiple ADC (analog to digital conversion) input pins as well as ordinary digital input and output pins.
DAC (digital to analog conversion) output pins aren’t really very useful for most sensor interface, but they wouldn’t hurt.
Also be sure that you either like the software that comes with it, or like the language that they allow you to program software for it in.