MAX7219 Four-in-One Dot Matrix Display Module

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  The four-in-one dot matrix display module uses the MAX7219 as a controller. It is an integrated serial input/output common cathode display driver that connects the microprocessor to an 8-digit 7-segment LED display, as well as to bar graph displays or 64 independent LEDs. It includes an on-chip BCD encoder, multiplex scanning circuits, segment drivers, and an 8*8 static RAM for storing each piece of data. There is only one external register to set the segment current for each LED. It can connect to all general-purpose microprocessors. Each data point can be addressed without needing to rewrite the entire display when updating.
  The entire device includes a low-power shutdown mode of 150μA, analog and digital brightness control, a scan limit register that allows users to display 1-8 digits of data, and a test mode that lights up all LEDs.

  You only need 3 IO pins to drive one dot matrix! The display is flicker-free! It supports cascading!

Module Source

Purchase Link: https://item.taobao.com/auction/noitem.htm?itemid=610275544833&catid=50018826&ali_refid=a3_430582_1006:1123524089:N:IDf%2BwN8Q0R0PQjZ6ZGtt%2BU%2F0kb%2F3OP%2Fb:a6ec0dd8bdb7b3e54d3715699fcd69b3&ali_trackid=1_a6ec0dd8bdb7b3e54d3715699fcd69b3&spm=a230r.1.14.1#detail

Baidu Netdisk Download Link:
https://pan.baidu.com/s/19WdOd8D2QlPi1Q_EWlb3fQ
Password:b822

Specifications

Operating Voltage:4-5.5V
Operating Current:8-330MA
Scanning rate:500-1300Hz
Communication protocol:Serial Communication
Pin Count:5 Pin (2.54mm pitch header)

Hardware Connection

For the four-in-one dot matrix module (typically containing four 8x8 matrices driven by a single MAX7219 chip), the connection is as follows:

• VCC: Connect to the development board's 5V.
• GND: Connect to the development board's GND.
• DIN: Data input, connect to a digital pin on the development board (for example, connect DIN to digital pin 11).
• CS: Chip select, also known as load (LOAD) or slave select (SS), connect to a digital pin on the development board (for example, connect CS to digital pin 10).
• CLK: Clock, connect to a digital pin on the development board (for example, connect CLK to digital pin 13).

Usage Method

Installing Library Files (skip this step if already installed)

1. Open the Arduino IDE.
2. Go to “Tools” > “Manage Libraries…”.
3. Install the LedControl library via "Manage Libraries" (search for LedControl in Tools > Library > Manage Libraries… and install it).

Enter the code:

/******************************************************************************
  * Test Hardware: LCSC ColorEasyDuino Development Board
  * Version Number: V1.0
  * Modified By: www.lckfb.com
  * Modification Date: March 28, 2024
  * Function Overview:
  *****************************************************************************
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******************************************************************************/
#include "LedControl.h"

// 参数分别是DIN, CLK, CS, 设备数量（现在是4）
LedControl lc = LedControl(11, 13, 10, 4);

void setup() {
  // 初始化所有模块
  for (int module = 0; module < 4; module++) {
    lc.shutdown(module, false);       // 启动模块（关闭省电模式）
    lc.setIntensity(module, 2);       // 设置亮度，0是最低，15是最高
    lc.clearDisplay(module);          // 清屏
  }
}

void loop() {
  for (int module = 0; module < 4; module++) {
    drawSmiley(module);
    delay(500);
  }

  // 清除所有模块的显示
  for (int module = 0; module < 4; module++) {
    lc.clearDisplay(module);
  }

  delay(500);
}

void drawSmiley(int module) {
  // 定义笑脸图案，1表示亮，0表示灭
  byte smiley[] = {
    B00111100,  //第一行
    B01000010,  //第二行
    B10100101,  //第三行
    B10000001,  //第四行
    B10100101,  //第五行
    B10011001,  //第六行
    B01000010,  //第七行
    B00111100   //第八行
  };

  // 遍历数组，绘制图案到指定模块
  for (int row = 0; row < 8; row++) {
    lc.setRow(module, row, smiley[]);
  }
}

Usage Testing