8X8 LED Matrix Using Arduino Microcontroller

Figure 1 

The circuit is driven by a MAX7219 IC that is being controlled through an Arduino microcontroller board, to create an 8X8 LED matrix.

The connection of the LED matrix and the IC was done on a customized PCB to clean up all the wires. In order to drain everything from the Arduino board, the design comes with a separate 12V power supply.

The MAX7219 driver IC is controlled by 4 wires only which include the data, clock, latch/load, and ground. The shiftOut command in Arduino is matched by the data and clock pins. After the shiftOut command, the latch pin will provide a LOW to HIGH pulse. There are two separate commands to shift both the upper and lower bytes to the MAX7219, since the Arduino can only shift 8 bits of data and 2 bytes of control is needed for each command.

A byte array-matrix of length 8 was used for the data structure of the 8X8 LED matrix. Each row in the matrix corresponds to the Y dimension while each bit in a row corresponds to the X dimension. The ON state is represented by 1 while 0 for OFF.