Rainbowduino v.3 Power + USB

Is it possible to have the Rainbowduino connected to an external power supply and USB at the same time? I have it programmed to take commands over the serial port, so it needs to stay plugged into my PC, but it would be nice to have the LEDs running off an external power supply because they are not very bright if it’s just running off of the USB power.

If that’s possible, any suggestions on what the specs for the power supply would be?

Yeah , that is possible to connected to an external power supply and USB at the same time . External 6V~12V DC