ESP32-C3 Super Mini MAX7219 4-in-1 NTP Matrix Clock

A modern, fast, and feature-rich NTP Digital Matrix Clock built for the ESP32-C3 Super Mini microcontroller and MAX7219 4-in-1 Dot Matrix Display Module (32x8 LED matrix).

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✨ Features

• Direct Hardcoded WiFi: Configured to connect directly to WiFi SSID 4D.
• NTP Time Synchronization: Automatic time syncing using ESP32 native POSIX timezone handlers with full Daylight Saving Time (DST) support.
• mDNS Support: Access the device control dashboard at http://clock.local directly from any phone or PC on your local network.
• Embedded Web Control Panel:
  • Live clock display & connection status.
  • Real-time brightness control slider (0 to 15).
  • 12-Hour / 24-Hour time format toggle.
  • Periodic date scrolling interval.
  • Dropdown menu with pre-configured POSIX timezones (IST, EST, CST, PST, GMT, CET, JST, AEST, UTC) or custom string.
  • Instant NTP sync button and System Restart button.
• Persistent Memory: All settings stored safely in ESP32 Preferences non-volatile flash storage.

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🔌 Hardware Wiring & Schematic

Connect the ESP32-C3 Super Mini board to the MAX7219 4-in-1 Dot Matrix Display:

MAX7219 Pin	ESP32-C3 Super Mini Pin	Notes
VCC	5V / 5V_IN	5V power supply
GND	GND	Ground connection
DIN	GPIO 7	Data (MOSI)
CLK	GPIO 6	Clock (SCK)
CS / LOAD	GPIO 5	Chip Select (Load)

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🛠️ Build & Upload Guide

Method A: PlatformIO (Recommended - Fast Upload)

1. Open this repository folder in VS Code with the PlatformIO extension installed.
2. Build and upload using terminal:

   pio run -t upload

3. Monitor serial output:

   pio device monitor

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Method B: Arduino IDE

1. Required Libraries (Tools > Manage Libraries):

   • MD_Parola
   • MD_MAX72XX
   • ArduinoJson

2. Board Settings:

   • Board: ESP32C3 Dev Module
   • USB CDC On Boot: Enabled
   • Upload Speed: 921600

3. Open ESPC3ClockMax7219.ino and click Upload.

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🌐 Web Dashboard Access

Once connected to your WiFi network:

• Open your browser and go to: http://clock.local