Let's start out that I'm VERY new to this. I really have no idea as to what I'm doing, I just have an idea.

I'd like to build a simple circuit that would allow me to monitor the voltage & current of external devices, in which a Laptop computer could display/chart the data realtime via USB? Ethernet?

The capabilities would, ideally cover everything from low voltage of under 5VDC/800ma to voltages and currents up to 220VAC/60amps. However, for my immediate needs, I'm looking for 12VDC up to 4amps.

I suppose I could tap into a multimeter, but I have no idea where, nor do I have any idea how to monitor it using a PC.

Thanks in advance!

 

See what this critter does for you - http://us.fluke.com/usen/products/features.htm?cs_id=37725(FlukeProducts)&category=BMM(FlukeProducts).

 

I have seen actual multimeters with RS-232 serial ports on them. Connecting one to a PC is a complete no brainer. You can gather readings with a terminal emulator like HyperTerm, TeraTerm, or similar programs.

 

I have a Radio Shack with an RS232 port, never used it, but it's there. They still sell them unless I'm mistaken.