Blog Posts | RBDIMMER

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AC Dimmer Flickering at Low Brightness Levels

Feb 26, 2026

0 36

FAQ

TL;DR: Irregular flicker at 5–25% brightness (stable at 50%+) is caused by ZC signal jitter, ISR delays from WiFi on ESP32/ESP8266, or TRIAC holding-current misses. Fix: set a minimum stable level (10...

ESP32 ac-dimmer halogen incandescent troubleshooting tutorial

Multi-Channel AC Dimmer Control: 2CH and 4CH Guide

Feb 26, 2026

0 31

FAQ

TL;DR: 2CH 8A and 4CH 10A modules share one ZC pin across all channels. Each channel has its own DIM pin. One interrupt call in code covers all channels; brightness is set independently per channel ha...

Arduino ESP32 ESP8266 RBDdimmer ac-dimmer multi-channel tutorial

AC Dimmer via MQTT with ESP32 and ESP8266

Feb 26, 2026

0 49

FAQ

TL;DR: Install rbdimmerESP32 (for ESP32) or RBDdimmer (for ESP8266) plus PubSubClient . Connect to your MQTT broker, subscribe to a brightness topic, and call rbdimmer_set_level() in the callback. Pub...

ESP32 MQTT ac-dimmer home-automation tutorial

AC Dimmer with Home Assistant: ESPHome and DimmerLink Guide

Feb 26, 2026

0 23

FAQ

TL;DR: Two integration paths exist. Path A (standard ESPHome ac_dimmer platform) is simple but causes ISR/WiFi conflicts on dual-core ESP32. Path B (DimmerLink ESPHome component) offloads TRIAC timing...

ESP32 ac-dimmer dimmerlink home-automation tutorial

ESPHome YAML for AC TRIAC Dimmer: Standard and DimmerLink

Feb 26, 2026

0 43

FAQ

TL;DR: Two ESPHome integration methods exist. The standard ac_dimmer platform works out-of-the-box but has ISR/WiFi conflicts on ESP32. The DimmerLink external component uses a hardware controller for...

ESP32 ac-dimmer dimmerlink esphome tutorial

Which AC Dimmer Module to Choose: Complete Buyer's Guide

Feb 26, 2026

0 35

FAQ

TL;DR: Three questions determine your choice: (1) load type — resistive (heater, incandescent) or inductive (motor); (2) load power in watts → calculate amps → pick a rating with a ×1.3 safety margin;...

Arduino ESP32 TRIAC ac-dimmer buyer-guide dimmerlink tutorial

Zero-Cross Not Detected: AC Dimmer Doesn't Respond to Commands

Feb 26, 2026

0 39

FAQ

TL;DR: An AC dimmer can't regulate the load if the microcontroller isn't receiving the zero-cross signal (the sine wave crossing zero). Without this signal it's impossible to calculate the TRIAC firin...

Arduino ESP32 ac-dimmer troubleshooting zero-cross

Wrong Library: RBDdimmer Instead of rbdimmerESP32 on ESP32

Feb 26, 2026

0 32

FAQ

TL;DR: For ESP32 you need rbdimmerESP32 — not the old RBDdimmer . The old library was written for Arduino AVR: no IRAM_ATTR , no core pinning, no race condition protection. On ESP32 it causes Guru Med...

Arduino ESP32 ac-dimmer troubleshooting

ESP32-S2/C3/H2: AC Dimmer Doesn't Work on Single-Core ESP32

Feb 26, 2026

0 38

FAQ

TL;DR: rbdimmerESP32 is designed for dual-core ESP32 (original and S3). ESP32-S2, C3, C6, and H2 are single-core. The library tries to isolate the dimmer task on a dedicated core — which is impossible...

ESP32 ac-dimmer dimmerlink troubleshooting

ESP32 + AC Dimmer: Guru Meditation Error and IRAM_ATTR — Causes and Fix

Feb 26, 2026

0 33

FAQ

TL;DR: If your ESP32 with an AC dimmer crashes ("Guru Meditation Error" or "Cache disabled but cached memory region accessed"), the cause is that the zero-cross ISR handler is not marked with IRAM_ATT...

ESP32 IRAM_ATTR WiFi ac-dimmer troubleshooting

AC TRIAC Dimmer Is Not PWM: How Phase-Cut Dimming Works

Feb 26, 2026

0 39

FAQ

TL;DR: analogWrite() and PWM don't work with an AC TRIAC dimmer. A TRIAC is not a resistor or a DC transistor. It regulates power using phase-cut control : it opens at a precisely calculated moment ea...

Arduino ESP32 TRIAC ac-dimmer troubleshooting

LED Flickering with AC Dimmer: TRIAC or MOSFET — Causes and Fixes

Feb 26, 2026

0 60

FAQ

Short answer: LED flickering with an AC dimmer has three distinct root causes. Types 1 and 2 are caused by TRIAC architectural incompatibility with LED lamps — the hardware fix is a MOSFET AC dimmer (...

Arduino ESP32 LED MOSFET TRIAC ac-dimmer flicker tutorial

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