DimmerLink Controller — UART/I2C Interface for AC Dimmers

Stop fighting with dimmer libraries. DimmerLink is a tiny plug-and-play controller that handles all the complex TRIAC timing for you. Just send simple commands over UART or I2C — the DimmerLink controller does the rest. Now available in 1-channel, 2-channel, and 4-channel versions.  

THE PROBLEM WE SOLVE

Every maker knows the pain: you integrate an AC dimmer library into your project, and suddenly your lights flicker, your timing breaks, and you spend hours debugging interrupt conflicts. With multi-channel setups it gets even worse — your MCU has to manage separate hardware timers for every channel, eating up resources and creating timing collisions. The DimmerLink eliminates this entirely by offloading all timing-critical operations to a dedicated Cortex-M+ microcontroller.

HOW IT WORKS

Connect DimmerLink between your MCU (Arduino, ESP32, Raspberry Pi, or any microcontroller) and your AC dimmer module. Send a 3-byte command like "SET CH0 50%" over UART or write to an I2C register. The controller handles zero-cross detection, phase angle calculation, and TRIAC triggering with microsecond precision for all channels simultaneously. No libraries to install. No interrupts to configure. No conflicts with your existing code.

The 2-channel and 4-channel versions have output pin sequences that match the RBdimmer 2CH and 4CH TRIAC dimmer modules directly — you can plug the DimmerLink straight onto the dimmer header, connect with jumper wires, or use a flat cable. Male and female 2.54mm pin headers are included in the package.

KEY FEATURES

• Zero flickering — hardware-based timing on all channels, immune to software delays
• 1 / 2 / 4 channel versions — matches RobotDyn TRIAC dimmer pinouts for direct connection
• Single bus, multiple channels — control all channels through one UART or I2C connection instead of wiring separate pins per dimmer
• Universal interface — UART (115200 baud) or I2C (address 0x50)
• Wide voltage range — works with 1.8V, 3.3V, and 5V logic levels
• Ultra-compact — standard 0.1" pin pitch, fits anywhere
• Multiple dimming curves — Linear, RMS, Logarithmic — individually configurable per channel
• Auto frequency detection — works with 50Hz and 60Hz mains

WHY MULTI-CHANNEL MATTERS

Without DimmerLink, controlling a 4-channel dimmer from an ESP32 requires 4 GPIO pins for dimming outputs + 1 zero-cross input, plus running 4 independent hardware timers with microsecond-precision ISRs — all competing for CPU time with your WiFi stack, sensors, and other tasks.

With DimmerLink 4CH: your MCU uses just 2 pins (SDA + SCL) or 2 pins (TX + RX). One simple command sets any channel. The Cortex-M+ handles all four timing-critical outputs from a single zero-cross signal with zero jitter. Your MCU is free to do what it does best — run your application logic.

Perfect for heater control, coffee roasters, reflow ovens, solar routers, lighting automation, and any project where stable multi-channel dimming matters.

Specifications:

Overview

• Quick Start
• Hardware Connection
• UART Communication
• I2C Communication
• Single Board Computers
• Advanced Usage
• FAQ & Troubleshooting