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DimmerLink — ESPHome Integration

Flicker-free AC dimming for Home Assistant. A dedicated timing controller that eliminates the #1 problem with TRIAC dimmers.

❌ The Problem

Using ESPHome's ac_dimmer component?

• 💡 Flickering at low brightness levels
• ⚡ WiFi conflicts — interrupts break timing
• 🔥 ESP8266 unstable — not enough resources for timing-critical code
• 📝 Complex tuning — timing depends on load type and mains quality

"The lamp has an irregular flicker" — ESPHome Issue #4131

✅ The Solution

DimmerLink — a compact module with dedicated Cortex-M0+ that handles ALL timing-critical operations: zero-cross detection, phase angle calculation, and TRIAC gate control with microsecond precision.

Your ESP just sends: "Set brightness to 50%" via I2C. That's it.

• ✅ Zero flickering — hardware-level timing, no software jitter
• ✅ 3 lines of YAML — no interrupts, no libraries, no conflicts
• ✅ Works on any ESP — ESP8266, ESP32, ESP32-S2/S3/C3
• ✅ Auto 50/60 Hz — automatic mains frequency detection
• ✅ 3 dimming curves — Linear, RMS, Logarithmic

DimmerLink vs ESPHome ac_dimmer

When to use ac_dimmer: If it already works well for your setup — keep using it!

When to use DimmerLink: Flickering issues, ESP8266, multiple dimmers, or you want plug-and-play simplicity.

• Product Page: DImmerLink on rbdimmer.com
• AliExpress Page: DImmerLink on AliExpress

Two Integration Methods

DimmerLink supports two approaches for ESPHome integration:

1. External Component (Recommended)

A ready-to-use ESPHome component with clean YAML configuration. No C++ or lambda code required.

external_components:
  - source: github://robotdyn-dimmer/DimmerLink@main
    components: [dimmerlink]
    refresh: 1d
dimmerlink:
  id: dimmer1
  address: 0x50
light:
  - platform: dimmerlink
    dimmerlink_id: dimmer1
    name: "Dimmer"

Best for: Most users. Simple YAML, automatic I2C communication, built-in sensors, selects, and buttons.

Full Component Documentation

2. Lambda Integration (Advanced)

Direct I2C register access using ESPHome lambda functions. Provides full control over communication protocol.

output:
  - platform: template
    id: dimmer_out
    type: float
    write_action:
      - lambda: |-
          uint8_t level = (uint8_t)(state * 100.0f);
          uint8_t data[2] = {0x10, level};
          id(bus_a).write(0x50, data, 2, true);
light:
  - platform: monochromatic
    name: "Dimmer"
    output: dimmer_out

Best for: Advanced users who need custom logic, non-standard configurations, or want to understand the I2C protocol in detail.

Full Lambda Documentation | Lambda Reference

Comparison of Integration Methods

Architecture

Home Assistant
      │
      │ WiFi (Native API)
      ▼
   ESP32 + ESPHome
      │
      │ I2C (100 kHz)
      ▼
  DimmerLink
      │
      │ Zero-Cross + Gate
      ▼
   AC Dimmer (TRIAC)
      │
      │ AC 110/220V
      ▼
    Lamp

Quick Start

Wiring

ESP32          DimmerLink
─────          ──────────
3.3V     →     VCC
GND      →     GND
GPIO21   →     SDA
GPIO22   →     SCL

Minimal Configuration (External Component)

esphome:
  name: dimmerlink
esp32:
  board: esp32dev
logger:
api:
ota:
wifi:
  ssid: "YOUR_WIFI"
  password: "YOUR_PASSWORD"
external_components:
  - source: github://robotdyn-dimmer/DimmerLink@main
    components: [dimmerlink]
    refresh: 1d
i2c:
  sda: GPIO21
  scl: GPIO22
dimmerlink:
  id: dimmer1
light:
  - platform: dimmerlink
    dimmerlink_id: dimmer1
    name: "Dimmer"
    gamma_correct: 1.0

Entity Types (External Component)

Related Documentation

Version History

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