Here, a common cathode 7-segment LED display is connected to Arduino for displaying the digits ... For testing purpose only one 330 Ohm resistor (R2) is added between ground rail (0V) and the common ...

[Christian] must have gotten bored with his awesome creation one day, because he pulled the drum level display out of his Arduino Sequencer 808, and turned the LED array into a mini Tetris game.

To get a LED lighting we should connect its ground pin to the circuit GND and the positive pin ... the VCC common anode of the board to one of the free digital pins of the Arduino? Setting the common ...