First off, please excuse my ignorance as I know very little about this stuff and searching google has only helped to confuse me more. What I would like to accomplish is to drive 12 bi-color LEDs (red/blue) from two seperate inputs. I would like the red potion of the LEDs to light when there is network activity and the blue LEDs to light when there is hard drive activity. This seems simple enough, but the bi-color LED is common cathode, and judging by the readings I took, the network and hard drive LEDs toggle the cathode to turn on or off the LEDs. So, what I was thinking is that I could use a transistor to drive the anodes of the 12 LEDs, but thats about as far as I got. The specs of the LEDs are Blue: 3.2v at 20mA and Red: 2.2v at 20mA. Also, the readings I took showed the hard drive activity LED cathode swinging from 5v (off) to 0v (on) and the network LED swinging from 3.3v (off) to 0v (on). Any drawing of a suitable circuit would be greatly appreciated and any explanation of how the circuit works would be even better! Thanks for any and all help!
-Jason