Zero-Cross Not Detected: AC Dimmer Doesn't Respond to Commands 26 feb 2026 0 9 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 Leggi di più
Wrong Library: RBDdimmer Instead of rbdimmerESP32 on ESP32 26 feb 2026 0 9 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 Leggi di più
TRIAC Overheating: AC Dimmer Runs Hot or Burns Out 26 feb 2026 0 9 TL;DR: A TRIAC is an active device with a voltage drop of ~1.2V. At load currents above 2A it dissipates several watts as heat. Without thermal management: overheating, thermal protection triggering, ... Arduino TRIAC ac-dimmer troubleshooting Leggi di più
ESP32-S2/C3/H2: AC Dimmer Doesn't Work on Single-Core ESP32 26 feb 2026 0 9 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 Leggi di più
ESP32 + AC Dimmer: Guru Meditation Error and IRAM_ATTR — Causes and Fix 26 feb 2026 0 8 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 Leggi di più
AC TRIAC Dimmer Is Not PWM: How Phase-Cut Dimming Works 26 feb 2026 0 11 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 Leggi di più
LED Lamps with AC Dimmer: TRIAC or MOSFET — Compatibility Guide 26 feb 2026 0 25 Short answer: There are two types of AC dimmers: TRIAC (leading edge — for incandescent bulbs, halogen, heaters) and MOSFET AC dimmer (trailing edge — purpose-built for LED lamps). If an LED lamp flic... Arduino LED MOSFET TRIAC ac-dimmer trailing-edge tutorial Leggi di più
Trailing Edge vs Leading Edge: Which Dimmer Method to Choose 26 feb 2026 0 25 Short answer: Leading edge is the standard TRIAC dimmer — it opens the load in the second half of each AC half-cycle (best for incandescent bulbs and heaters). Trailing edge is a MOSFET dimmer — it op... Arduino LED MOSFET TRIAC ac-dimmer leading-edge trailing-edge tutorial Leggi di più
LED Flickering with AC Dimmer: TRIAC or MOSFET — Causes and Fixes 26 feb 2026 0 27 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 Leggi di più