ESP32 + AC Dimmer: Guru Meditation Error and IRAM_ATTR — Causes and Fix 26 févr. 2026 0 19 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 En savoir plus