The Xadow LED 5x7 contains two parts: a LED panel and a LED controller. The LED panel is a 5x7 Monochrome matrix. The LED controller is a control module for controlling the LED panel using 12 I/O pins of the Atmega168PV. You can send commands to LED controller through an IIC interface controlling the LED display. For example, display a letter and number, or enter sleep mode to reduce the consumption.