Power can provided to the Application Board from either the main power connector, or the USB connector. Generally, the power from the USB connector is only enough for powering the board itself (great for programming and testing), but not for driving devices more powerful than an LED. To drive anything more than the smallest devices, it is a better idea to power the Application Board from the main power connector using a 9V wall adapter. The board can be run on anywhere from 6 - 12V, but higher voltages mean that the board is doing extra work to produce the 3.3V and 5V lines needed by the onboard electronics.

Be sure that your power supply provides enough current to drive the devices you have connected to the board. Almost all devices and power supplies list a current rating - be sure the combined current of your devices does not exceed the rating of your supply.