ARDUINO 101 | MAX7219 8X8 DOT MATRIX

In this Instructable we will learn how to interface an 8 by 8 LED dot matrix display with an Arduino Uno.

Let's first try to understand the principle of operation of the display.

The display consists of 8 rows and 8 columns arranged as shown:

C1 C2 C3 C4 C5 C6 C7 C8

R1 0 0 0 0 0 0 0 0

R2 0 0 0 0 0 0 0 0

R3 0 0 0 0 0 0 0 0

R4 0 0 0 0 0 0 0 0

R5 0 0 0 0 0 0 0 0

R6 0 0 0 0 0 0 0 0

R7 0 0 0 0 0 0 0 0

R8 0 0 0 0 0 0 0 0

To display a particular character, we need to illuminate the LEDs that will make up the pattern. For example, if we have to display the character "A", we need to turn on the following LEDs:

C1 C2 C3 C4 C5 C6 C7 C8

R1 0 0 1 1 1 1 0 0

R2 0 1 1 0 0 1 1 0

R3 1 1 0 0 0 0 1 1

R4 1 1 0 0 0 0 1 1

R5 1 1 1 1 1 1 1 1

R6 1 1 0 0 0 0 1 1

R7 1 1 0 0 0 0 1 1

R8 1 1 0 0 0 0 1 1

We can see that the '1's make up a pattern that describes the character "A"

1) Arduino Uno: Buy here.

2) MAX7219 8x8 LED Dot Matrix Display: Buy here.

VCC -> VCC

GND -> GND

DIN -> Digital Pin 7

CLK -> Digital Pin 5

CS -> Digital Pin 6

1) Download the file.

2) Open it up on the Arduino IDE.

3) Verify and upload the code.

* SKIP TO 2:33 *

Just sit back and relax as your display cycles through the 26 letters in the English alphabets!