Download & install source code for Esp8266 Board & Max7219 : Download Matrix Display Clock Esp8266 Board : https://amzn.to/3dPXuZu Max7219 Display : https://amzn.to/3s4qpl4 #include "Arduino.h" #include WiFiClient client; String date; #define NUM_MAX 4 #define LINE_WIDTH 16 #define ROTATE 90 // for NodeMCU 1.0 #define DIN_PIN 15 // D8 #define CS_PIN 13 // D7 #define CLK_PIN 12 //