Disabling auto power select on Seeeduino Mega

Hi all,

I have a Seeeduino Mega that I am powering externally, but I also have the USB cable attached. The problem is that I would like to be able to turn off my Mega without also needing to remove the USB cable. (There is a long-winded reason for this…)

I loved the jumper on the Diecimila that manually selected it, but this auto-select on the mega is a little annoying IMHO.

Can such a thing be done? (I hear that early revisions of the board had a selectable power supply, but v1.22 doesn’t)