ESP32-S3 RGB LED 매트릭스 Wi-Fi + NTP 시간 시계 프로젝트 -1 기본 시계

/*
This is ESP32 sketch that connects to the internet, gets the time and displays it on the RGB matrix
you must set your WiFi correctly to make sure it gets connected. 
 watch video https://youtube.com/shorts/4iWjLiD7fS8
 📚⬇️ Download and resource page https://robojax.com/RJT838
 * Author:  Ahmad Shamshiri (Robojax.com)
 * Date: 07 Jan 2026
www.Robojax.com
https://youTube.com/@robojax


*/
#include <WiFi.h>
#include "time.h"
#include <Adafruit_GFX.h>
#include <Adafruit_NeoMatrix.h>
#include <Adafruit_NeoPixel.h>

//set the color of diplay make of Red, Green and Blue 
unsigned int color_RED = 17;
unsigned int color_GREEN = 43;
unsigned int color_BLUE = 171;

// 👇 REPLACE these with your real home WiFi name & password
const char* WIFI_SSID     = "WiFi";
const char* WIFI_PASSWORD = "passW0rd";



#define MATRIX_PIN 14

Adafruit_NeoMatrix matrix(8, 8, MATRIX_PIN,
  NEO_MATRIX_TOP    + NEO_MATRIX_LEFT +
  NEO_MATRIX_ROWS   + NEO_MATRIX_PROGRESSIVE,
  NEO_RGB           + NEO_KHZ800);

char timeText[6] = "00:00";
int16_t scrollX = 8;
unsigned long lastScrollMs = 0;
const uint16_t scrollIntervalMs = 120;

unsigned long lastTimeUpdateMs = 0;
const uint16_t timeUpdateIntervalMs = 1000;

//prototypes
bool updateTimeText();  // forward declaration
void scrollTime();      // forward declaration



// NTP (time) server
const char* ntpServer = "pool.ntp.org";

// Toronto-ish: UTC-5, plus 1 hour DST
const long  gmtOffset_sec     = -5 * 3600;  // -5 hours
const int   daylightOffset_sec = 3600;      // +1 hour for DST



bool updateTimeText() {
  struct tm timeinfo;
  if (!getLocalTime(&timeinfo)) {
    Serial.println("Failed to obtain time for display");
    return false;
  }

  // Format HH:MM
  snprintf(timeText, sizeof(timeText), "%02d:%02d",
           timeinfo.tm_hour,
           timeinfo.tm_min);

  Serial.print("Time text: ");
  Serial.println(timeText);
  return true;
}

void scrollTime() {
  matrix.fillScreen(0);
  matrix.setCursor(scrollX, 0);
  matrix.print(timeText);
  matrix.show();

  scrollX--;

  // Rough width: 5 characters ("HH:MM") × 6 pixels each ≈ 30 px
  int16_t textWidth = 30;
  if (scrollX < -textWidth) {
    scrollX = matrix.width();  // reset to right edge (8)
  }
}


void initMatrix() {
  matrix.begin();
  matrix.setBrightness(40);        // be careful with heat
  matrix.setTextWrap(false);
  matrix.setTextColor(matrix.Color(color_RED, color_GREEN, color_BLUE)); // color of text
}

void showMessage(const char* msg) {
  matrix.fillScreen(0);
  matrix.setCursor(0, 0);  // top-left
  matrix.print(msg);
  matrix.show();
}


void printLocalTime() {
  struct tm timeinfo;
  if (!getLocalTime(&timeinfo)) {
    Serial.println("Failed to obtain time");
    return;
  }
  // Format: 2025-11-18 14:35:12
  Serial.printf("%04d-%02d-%02d %02d:%02d:%02d\n",
                timeinfo.tm_year + 1900,
                timeinfo.tm_mon + 1,
                timeinfo.tm_mday,
                timeinfo.tm_hour,
                timeinfo.tm_min,
                timeinfo.tm_sec);
}

void setup() {
  Serial.begin(115200);
  delay(1000);
  Serial.println();
  Serial.println("ESP32-S3 Internet Clock - WiFi + NTP test");

  // Connect to WiFi
  Serial.print("Connecting to WiFi: ");
  Serial.println(WIFI_SSID);
  WiFi.mode(WIFI_STA);
  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);

  int retries = 0;
  while (WiFi.status() != WL_CONNECTED && retries < 30) { // ~15s timeout
    delay(500);
    Serial.print(".");
    retries++;
  }
  Serial.println();

  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("WiFi connection FAILED");
  } else {
    Serial.print("WiFi connected. IP: ");
    Serial.println(WiFi.localIP());
  }

// if user set all colors to 0, the dispaly will be turned off so set it green
  if(color_RED ==0 & color_GREEN ==0 && color_BLUE ==0)
  {
    color_GREEN = 200;
  }

  // Configure time via NTP
  configTime(gmtOffset_sec, daylightOffset_sec, ntpServer);
  Serial.println("Waiting for time...");
  delay(2000); // small wait for initial sync

  printLocalTime(); // print once at startup

    // NEW: init the LED matrix and show a test message
  initMatrix();
  showMessage("OK");
}

void loop() {
  unsigned long now = millis();

  // Update the time string "HH:MM" once per second
  if (now - lastTimeUpdateMs >= timeUpdateIntervalMs) {
    lastTimeUpdateMs = now;
    updateTimeText();  // fills timeText[], e.g. "14:32"
  }

  // Scroll the time across the 8×8 every scrollIntervalMs
  if (now - lastScrollMs >= scrollIntervalMs) {
    lastScrollMs = now;
    scrollTime();      // uses timeText and scrollX
  }
}