Wrong Library: RBDdimmer Instead of rbdimmerESP32 on ESP32 Feb 26, 2026 0 426 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... ac-dimmer Arduino ESP32 troubleshooting Read more
TRIAC Overheating: AC Dimmer Runs Hot or Burns Out Feb 26, 2026 0 388 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, ... ac-dimmer Arduino TRIAC troubleshooting Read more
ESP32-S2/C3/H2: AC Dimmer Doesn't Work on Single-Core ESP32 Feb 26, 2026 0 547 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... ac-dimmer dimmerlink ESP32 troubleshooting Read more
ESP32 + AC Dimmer: Guru Meditation Error and IRAM_ATTR — Causes and Fix Feb 26, 2026 0 428 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... ac-dimmer ESP32 IRAM_ATTR troubleshooting WiFi Read more
AC TRIAC Dimmer Is Not PWM: How Phase-Cut Dimming Works Feb 26, 2026 0 482 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... ac-dimmer Arduino ESP32 TRIAC troubleshooting Read more
LED Lamps with AC Dimmer: TRIAC or MOSFET — Compatibility Guide Feb 26, 2026 0 554 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... ac-dimmer Arduino LED MOSFET trailing-edge TRIAC tutorial Read more
Trailing Edge vs Leading Edge: Which Dimmer Method to Choose Feb 26, 2026 0 662 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... ac-dimmer Arduino leading-edge LED MOSFET trailing-edge TRIAC tutorial Read more
LED Flickering with AC Dimmer: TRIAC or MOSFET — Causes and Fixes Feb 26, 2026 0 537 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 (... ac-dimmer Arduino ESP32 flicker LED MOSFET TRIAC tutorial Read more