Hey guys, I'm in a bit of a struggle here...
I wanna have my full room led lit, ambilight, PC case lighting, closet and everything, wich I was able to set up... For the most part.
I am currently controlling most parts separately, with independent Arduinos and power sources. But since controlling all of them got kinda complicated, I wanted to connect them all. Either wirelessly, but that might get expensive, so if possible, something else would be appreciated, or I simply connect all the Arduinos together/all the LEDs to one Arduino.
The problem is: the Arduino has to be connected to the pc via USB, and I don't have a PSU powerful enough to drive all the LEDs. Can I power some of the LEDs with an external PSU if I connect all the grounds together? Since the potentials would be equal, I wouldn't have any signal problems, but wouldn't such an approach lead to relatively hight current flowing between my power supplies???
I appreciate any help, I'm mainly just worried to fry my PC PSU by doing that, since I draw part of the power from my molex 4-pin connectors and the additional current flowing might hurt it... As I said, I don't know how to approach this... 
