I'm currently trying to use an Uno with two stackable shields and an Xbox 360 Controller:
So far, I've only been successful in connecting the Xbox 360 controller when the Arduino is connected to the computer via USB for power and the USB shield ontop. But whenever I put the screw shield in between the arduino and the USB shield (still using USB as power), the xbox controller's lights flash once and then remains powered off. I've tried connecting an external power source, both with and without the USB power plugged in, to the arduino using the 2.1mm barrel connector and through the VIN/ground pins, but nothing seems to keep power to the xbox xontroller except for just using the USB to pc as power and only using the USB shield ontop of the arduino.
I need to be able to use the screw shield as I'm planning to use multiple servos linked to the xbox controller. I was hoping if anyone could help me out as I don't know how to read the shield schematics, and was beginning to wonder if the USB shield I purchased only functions while the arduino is powered via USB. I'm almost positive that the xbox controller not lighting up is due to a power problem, but I've only just begun using arduinos so any help would be greatly appreciated!