LED AC Dimmer Control Center

Control your 6 LEDs in series via AC Dimmer Module with a modern web interface!

Hardware Setup

Components Needed

• Arduino board (Uno, Nano, Mega, etc.)
• AC Dimmer Module (240V/8A)
• 6 LEDs in series (or incandescent lamps)
• Connecting wires
• USB cable for Arduino

Wiring - IMPORTANT!

Arduino to AC Dimmer Module:

• Dimmer Zero Pin → Arduino Pin 2 (MUST be interrupt pin - D2 on Uno/Nano)
• Dimmer DIM Pin → Arduino Pin 9 (can be any digital pin)
• Dimmer VCC → Arduino 5V
• Dimmer GND → Arduino GND

AC Dimmer to LEDs:

• Connect your 6 LEDs in series to the AC dimmer module's output terminals
• Connect AC input (120V or 240V) to dimmer's input terminals
• ⚠️ WARNING: Handle AC connections with extreme care!

Arduino to Computer:

• USB cable from Arduino to your laptop

Software Setup

Step 1: Install RBDdimmer Library

1. Open Arduino IDE
2. Go to: Sketch → Include Library → Manage Libraries
3. Search for: "RBDdimmer"
4. Click Install on "RBDdimmer by RobotDyn"
5. Wait for installation to complete

Step 2: Upload Arduino Code

1. Open led_controller.ino in Arduino IDE
2. Select your Arduino board: Tools → Board
3. Select the correct COM port: Tools → Port
4. Click the Upload button (→)
5. Wait for "Done uploading" message

Step 3: Open Control Center

1. Open control_center.html in Google Chrome or Microsoft Edge
2. Click "Connect to Arduino"
3. Select your Arduino's COM port from the popup
4. Click "Connect"

Using the Control Center

Connection

• Connect to Arduino: Opens port selector
• Disconnect: Closes serial connection
• Green indicator: Connected and ready

Controls

• Power Toggle: Turn LEDs ON/OFF
• Brightness Slider: Adjust from 0% to 100%
• ☀️ Sunrise Button: Automatically fade from 0→100% over 5 minutes

Status Display

• State: ON/OFF status
• Brightness: Current percentage
• Mode: NORMAL or SUNRISE

Console

• Shows all commands and responses
• Color-coded: Green (sent), Blue (received), Red (errors)

Communication Protocol

Commands (PC → Arduino)

• ON - Turn LEDs on
• OFF - Turn LEDs off
• BRIGHTNESS75 - Set brightness to 75% (0-100)
• SUNRISE_START - Start 5-minute sunrise simulation
• SUNRISE_STOP - Stop sunrise simulation
• STATUS - Request current status

Responses (Arduino → PC)

• STATUS:ON:75:NORMAL - LEDs ON at 75%, normal mode
• STATUS:ON:45:SUNRISE - LEDs ON at 45%, sunrise mode active
• SUNRISE:STARTED - Sunrise simulation started
• SUNRISE:COMPLETE - Sunrise simulation finished

Troubleshooting

Cannot upload to Arduino

• Close Arduino Serial Monitor (locks the port)
• Check USB cable connection
• Verify correct board and port selected

"RBDdimmer.h: No such file" error

• Install RBDdimmer library (see Step 1 above)
• Restart Arduino IDE after installation

Dimmer not working

• Check Zero pin: MUST be on interrupt pin (D2 on Uno/Nano)
• Verify wiring: Zero → Pin 2, DIM → Pin 9
• AC power: Ensure AC dimmer has proper AC input
• Load type: Works best with incandescent/resistive loads

Interrupt Pin Reference

Different Arduino boards use different interrupt pins:

• Uno/Nano: Pin 2 (INT0), Pin 3 (INT1)
• Mega: Pins 2, 3, 18, 19, 20, 21
• Leonardo: Pins 0, 1, 2, 3, 7

If using a different board, change ZERO_CROSS_PIN in the code to match available interrupt pins.

LEDs flicker or unstable

• AC dimmers work best with incandescent bulbs
• Some LED bulbs may not be dimmable
• Ensure proper load (not too low, not exceeding 8A)

Technical Details

• Control Method: AC phase-angle control with zero-crossing detection
• Library: RBDdimmer.h by RobotDyn
• Interrupt Pin: Pin 2 (INT0 on Uno/Nano)
• Control Pin: Pin 9 (digital)
• Baud Rate: 9600
• Brightness Range: 0-100%
• Sunrise Duration: 5 minutes (300 seconds)

Safety Warning ⚠️

This project involves AC mains voltage (120V/240V) which can be LETHAL!

• Only work on AC connections when power is OFF
• Use proper insulation and enclosures
• If unsure, consult a licensed electrician
• Never touch AC connections while powered
• This is for educational purposes only

Features

✨ Professional AC dimming control
🌅 5-minute sunrise simulation
🎨 Dark mode with premium UI
⚡ Real-time serial communication
🔌 Web Serial API (no drivers needed)
📊 Live status and mode indicators
🎯 RBDdimmer library integration

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Enjoy your smart LED dimming system! 💡