MAX7219 8×8 LED Dot Matrix Display Module
This is Dot LED Matrix Module incorporating the MAX72
The MAX7219 is an IC designed to control an 8×8 LED MATRIX. The IC is serial input common-cathode (Common Negative) display drivers that interface microprocessors (or microcontroller) to 7-segment numeric LED displays of up to 8 digits, bar-graph displays, or 64 individual LEDs.
The individual module features 8×8 LED’s, each controlled very precisely by the MAX7219 driver to generate the color pattern you wish. The IC is capable of driving 64 individual LEDs while using only 3 wires for communication with the Arduino.
The 64 LEDs are driven by 16 output pins of the IC.the maximum number of LEDs light up at the same time is actually eight. The LEDs are arranged as 8×8 set of rows and columns. So the MAX7219 activates each column for a very short period of time and at the same time it also drives each row. So by rapidly switching through the columns and rows the human eye will only notice a continuous light.
It is the arrangement of LEDs in matrix form to display time, temperature, news updates, etc. LEDs can be arranged in the matrix form by two ways. Either row is anode and the column is a cathode or vice-versa. The LED layer is fixed to the bottom of the segments. When power is on, LEDs will glow.
The above-given figure indicates the structure of the 8X8 LED Dot-matrix.
The MAX7219 Dot Led Matrix Module is a serial input common-cathode driver that interfaces microcontrollers to LED matrices. All common micro-controllers can be connected to this module by using a 4-wire serial interface. Each output can be addressed without refreshing the entire display. This module requires only 3 I/O lines for driving the display, making it ideal for your microcontroller projects. Only one external register is used to set the segment current of each LED.
You only need to connect 5 pins from the dot matrix to your Arduino board.
Dot-matrix pin Wiring to Arduino Uno
DIN Digital pin
CS Digital pin
CLK Digital pin