I have a USB controlled device (Razer DeathAdder Chroma) that has an RGB LED on it and I would like to use that LED to control a 5050 RGB LED strip about a meter in length. Both the "input" LED and the strip are common anode with the "input" LED's + pin at just over 3V and the strip's at just over 12V.
I planned on following the adafruit RGB LED Strip tutorial with the gate on the MOSFETs being connected to the "input" LED. The problem I run into is which ground do I use? The ground from the 12V supply that's powering the strip or the ground pin on the USB device.
Pictures of the LED and a segement of the LED strip.
Any advice would be greatly appreciated and thank you in advance!