Hardware Connection

Wiring diagrams for connecting DimmerLink to popular microcontrollers and single-board computers.

DimmerLink Connectors

Input Connector (to your project)

Output Connector (to dimmer module)

Compatibility

DimmerLink supports a wide range of supply voltages and logic levels:

✅ Direct connection to any microcontroller without level converters!

General Connection Diagram

┌─────────────────┐      ┌──────────────────┐      ┌─────────┐      ┌──────┐
│  Your Project   │      │   DimmerLink     │      │ Dimmer  │      │ Lamp │
│  (Arduino/RPi)  │◄────►│                  │◄────►│ (TRIAC) │◄────►│      │
└─────────────────┘      └──────────────────┘      └─────────┘      └──────┘
     UART/I2C                                         AC 220V

Supported Platforms

DimmerLink works with any microcontroller that has UART or I2C interface.

Any controller with UART or I2C connects directly!

I2C Connection

Requirements

• Pull-up resistors: Many controllers already have I2C pull-ups. Add 4.7kΩ resistors on SDA and SCL to VCC
• Speed: 100 kHz (Standard Mode)
• Address: 0x50

I2C Wiring Diagram

                    VCC (your board)
                     │
                ┌────┴────┐
               4.7kΩ     4.7kΩ
                │         │
┌───────────┐   │         │   ┌──────────────────┐
│           │   │         │   │   DimmerLink     │
│   Your    │───┴─────────│───│ SDA              │
│  Project  │             │   │                  │
│   SDA     │─────────────┴───│ SCL              │
│   SCL     │                 │                  │
│   GND     │─────────────────│ GND              │
│   VCC     │─────────────────│ VCC              │
└───────────┘                 └──────────────────┘

Dimmer Connection

Arduino Uno / Nano

I2C Connection

UART Connection

📝 Note: On Arduino Uno, pins 0/1 are used for USB. SoftwareSerial is recommended.

#include 
SoftwareSerial dimmerSerial(10, 11);  // RX, TX

void setup() {
    dimmerSerial.begin(115200);
}

Arduino Mega

I2C Connection

UART Connection

Arduino Mega has 4 hardware UARTs (Serial, Serial1, Serial2, Serial3).

ESP8266 (NodeMCU, Wemos D1)

I2C Connection

UART Connection

📝 Note: GPIO1/GPIO3 are used for USB. Alternatives:
- Use Serial.swap() to remap to GPIO15/GPIO13
- Or use I2C instead of UART

ESP32

I2C Connection

I2C pins can be remapped:

Wire.begin(SDA_PIN, SCL_PIN);

UART Connection

ESP32 has 3 hardware UARTs (Serial, Serial1, Serial2).

STM32 Blue Pill

I2C Connection

UART Connection

Raspberry Pi Pico

I2C Connection

UART Connection

Raspberry Pi 3/4/5

I2C Connection

Enabling I2C:

sudo raspi-config
# Interface Options → I2C → Enable

UART Connection

Enabling UART:

sudo raspi-config
# Interface Options → Serial Port → Enable

Orange Pi / Banana Pi

Connection is similar to Raspberry Pi, but GPIO numbers may differ.

Orange Pi (e.g., Orange Pi Zero)

⚠️ Warning: GPIO pinout differs between models! Check your specific board's documentation.

General principle:
1. Find I2C pins in your board's documentation
2. Connect SDA → SDA, SCL → SCL
3. Add 4.7kΩ pull-up resistors

Banana Pi (e.g., Banana Pi M2)

📝 Note: Check documentation for your specific Orange Pi / Banana Pi model.

I2C Pull-up Resistors

For reliable I2C operation, pull-up resistors are required.

When External Pull-ups Are Needed

Calculating Value

• Short wires (< 10 cm): 4.7kΩ - 10kΩ
• Medium wires (10-50 cm): 2.2kΩ - 4.7kΩ
• Long wires (> 50 cm): 1kΩ - 2.2kΩ (not recommended)

Installation Recommendations

1. Keep wires short — I2C is sensitive to length, keep wires under 30 cm
2. Shielding — For long runs, use shielded cable
3. Separate power — Use separate power supply for DimmerLink if main supply is unstable
4. Decoupling — Add 100nF capacitor between VCC and GND near DimmerLink

Connecting to Other Controllers

DimmerLink works with any microcontroller that has UART or I2C:

• PIC: Connect to MSSP (I2C) or EUSART (UART)
• AVR (ATmega, ATtiny): TWI for I2C, USART for UART
• MSP430: eUSCI modules
• nRF52: TWIM/UARTE peripherals
• RISC-V (ESP32-C3, GD32VF103): Standard I2C/UART

General principle:
1. Find I2C/UART pins in documentation
2. Connect according to tables above
3. Add pull-ups for I2C
4. Done!