Running on external power
Having just downloaded an example sketch to the Maple, testing was fine. Then I switched over to my 5v supply while moving the Power select jumper to EXT. Still fine. But as soon as I disconnect the USB, the shield stops working. My first idea was that the power was insufficient and that some extra was drawn from the USB. But even after powering down the hub and pulling it from the computer, it worked. So I dissected a mini USB and tested. It appears that if short circuit the data lines to the V in the USB cable, it works. But as soon as I unplug it from the Maple, the shield goes silent. What is causing this?