DimmerLink - AC Dimmer controller, UART/I2C interface, FLICKER-FREE, NO LIBRARIES REQUIRED

DimmerLink — User Documentation

RBDIMMER.COM

Techincal support, user guide, community support

AC dimmer controller for lamp brightness control via TRIAC. Connects to your project (Arduino, ESP32, Raspberry Pi, etc.) and allows you to control AC dimmers with simple commands.

Working with DimmerLink is easy.

Key Features

✅ FLICKER-FREE — Dedicated Cortex-M+ handles all critical timings. No software delays, interrupt conflicts, or flickering.

✅ NO LIBRARIES REQUIRED — Send simple 3-4 byte commands via UART or I2C. Works with any programming language. Literally 5 lines of code.

✅ UNIVERSAL COMPATIBILITY — Arduino, ESP32, ESP8266, Raspberry Pi, STM32, any MCU with UART/I2C. Supports 1.8V, 3.3V, 5V logic levels.

✅ BRIGHTNESS CONTROL — 0-100% range

✅ DIMMING CURVES — Linear, RMS (for incandescent), Logarithmic. Auto-detection of 50/60Hz mains frequency.

✅ MAINS DETECTION — Automatic mains frequency detection (50/60 Hz)

✅ DUAL INTERFACE — UART (115200 8N1) or I2C. Switch by command at any time.

✅ ULTRA-COMPACT — Only 18×12mm. Standard 0.1" pins. Fits in any enclosure.

✅ PLUG & PLAY — Connect, power up, send command. Working dimmer in 5 minutes.

The Problem We Solve

Every maker knows this pain: you add an AC dimmer library to your project, and suddenly your lamps start flickering, timings go haywire, and you spend hours debugging interrupt conflicts. DimmerLink completely eliminates this problem by offloading all time-critical operations to a dedicated Cortex-M+ microcontroller.

How It Works

Connect DimmerLink between your controller (Arduino, ESP32, Raspberry Pi, or any MCU) and an AC dimmer module. Send a 3-byte command like 

SET 50%

 via UART or write a value to an I2C register. The controller handles zero-cross detection, calculates phase angle, and controls the TRIAC with microsecond precision. No libraries. No interrupts. No conflicts with your code.

Or connect to remote transmission modules like LoRa, GSM/GPRS, Bluetooth or WiFi bridges, or simply to your PC via USB-UART modules like CH340, CP2102/CP2104. Industrial RS-232 modules. No code required, just commands via terminal.

Which Interface to Choose?

💡 Tip: We recommend I2C for beginners — simpler code, clearer structure.

Compatibility

DimmerLink supports 1.8V, 3.3V and 5V logic levels — direct connection without level converters!

This is just a basic list — DimmerLink works with any microcontroller that has UART or I2C!

Quick Example

Arduino + I2C — set brightness to 50%:

===========

#include

void setup() {

Wire.begin();

// Set brightness to 50%

Wire.beginTransmission(0x50);

Wire.write(0x10); // Brightness register

Wire.write(50); // 50%

Wire.endTransmission();

}

void loop() {}

===========

Python + UART:

===========

import serial

ser = serial.Serial('/dev/ttyUSB0', 115200)

ser.write(bytes([0x02, 0x53, 0x00, 50])) # SET dimmer 0 to 50%

response = ser.read(1)

print("OK" if response[0] == 0 else "Error")

===========

Serial Terminal Example:

1. Port → select your COM port

2. Baud: 115200

3. Send → "Send Numbers" tab

4. Enter: 02 53 00 32 or 0x02 0x53 0x00 0x32 (HEX 32 is 50 in decimal)

5. Click "Send Numbers"

Quick Start

This guide will help you get DimmerLink up and running in minutes.

What You'll Need

DimmerLink — controller board

Dimmer — TRIAC module with external control support

Microcontroller or SBC — Arduino, ESP32, Raspberry Pi, etc.

Jumper wires

Lamp for testing (incandescent or dimmable LED)

Step 1: Choose an Interface

💡 Tip: We recommend starting with I2C — simpler code, easier debugging.

Step 2: Wiring

DimmerLink Connectors

Input (to your project):

Output (to dimmer module):

Connection Diagram

[Your Project] ←→ [DimmerLink] ←→ [Dimmer] ←→ [Mains + Lamp]

Step 3: Upload Code

Option A: I2C (Recommended)

Arduino:

==========

#include

#define DIMMER_ADDR 0x50

#define REG_LEVEL 0x10

void setup() {

Wire.begin();

}

void loop() {

// Smooth brightness change

for (int level = 0; level <= 100; level += 10) {

setLevel(level);

delay(500);

}

for (int level = 100; level >= 0; level -= 10) {

setLevel(level);

delay(500);

}

}

void setLevel(uint8_t level) {

Wire.beginTransmission(DIMMER_ADDR);

Wire.write(REG_LEVEL);

Wire.write(level);

Wire.endTransmission();

}

==========

MicroPython (ESP32, Raspberry Pi Pico):

==========

from machine import I2C, Pin

import time

# ESP32: scl=22, sda=21

# Raspberry Pi Pico: scl=5, sda=4

i2c = I2C(0, scl=Pin(22), sda=Pin(21), freq=100000)

DIMMER_ADDR = 0x50

REG_LEVEL = 0x10

def set_level(level):

i2c.writeto_mem(DIMMER_ADDR, REG_LEVEL, bytes([level]))

# Smooth brightness change

while True:

for level in range(0, 101, 10):

set_level(level)

time.sleep(0.5)

==========

Python (Raspberry Pi):

==========

from smbus2 import SMBus

import time

bus = SMBus(1)

DIMMER_ADDR = 0x50

REG_LEVEL = 0x10

def set_level(level):

bus.write_byte_data(DIMMER_ADDR, REG_LEVEL, level)

# Set brightness to 50%

set_level(50)

==========

Option B: UART

Arduino:

==========

// Use Serial1 (or SoftwareSerial for Uno)

#define DIMMER_SERIAL Serial1

void setup() {

DIMMER_SERIAL.begin(115200);

checkConnection();

}

void loop() {

setLevel(50); // 50%

delay(2000);

setLevel(100); // 100%

delay(2000);

}

void setLevel(uint8_t level) {

uint8_t cmd[] = {0x02, 0x53, 0x00, level};

DIMMER_SERIAL.write(cmd, 4);

// Wait for response

delay(10);

if (DIMMER_SERIAL.available()) {

uint8_t response = DIMMER_SERIAL.read();

// 0x00 = OK

}

}

// Connection check — request mains frequency

void checkConnection() {

uint8_t cmd[] = {0x02, 0x52};

Serial1.write(cmd, 2);

delay(50);

if (Serial1.available() >= 2) {

uint8_t status = Serial1.read();

uint8_t freq = Serial1.read();

if (status == 0x00) {

Serial.print("OK! Mains frequency: ");

Serial.print(freq);

Serial.println(" Hz");

}

}

}

==========

Python:

==========

import serial

import time

ser = serial.Serial('/dev/ttyUSB0', 115200, timeout=0.1)

def set_level(level):

cmd = bytes([0x02, 0x53, 0x00, level])

ser.write(cmd)

response = ser.read(1)

return len(response) > 0 and response[0] == 0x00

# Set brightness to 50%

if set_level(50):

print("OK")

else:

print("Error")

==========

Step 4: Verify Operation

Upload the code to your microcontroller

Power up DimmerLink

Observe — the lamp should change brightness