This is a 14×9 matrix of red LEDs mounted on a PCB that can be attached to the Pi and controlled via the GPIO header. The 126 LEDs can be turned on individually or used to display scrolling text.
The PI Matrix Shield using standard serial communications, it\'s really simple to send text and graphics to the 126 LED\'s. The matrix is powered from an ATMega328p processor which means all the processing of driving the 126 LED\'s is off loaded from the Pi\'s processor. This frees the Pi\'s processor and GPIO for other functions.