Connecting LEDs to AVR-P28

Hey, i want to expand the P28 Board with some LEDs.

But i don’t know which pin of the Power Jack is VCC and with is Ground.

Under the Power Jack there are 3 pins, to which one do i have to connect the LED?

thanks

All the holes along the top of the AVR-p28 are VCC. The holes along the bottom are GND. You can verify this with a voltmeter.