Plug-and-play AC dimmer controller with UART/I2C interface. No library required — send 3-4 byte commands from Arduino, ESP32, Tasmota, ESPHome, Raspberry Pi or any MCU. Dedicated Cortex-M+ handles all timing: zero flickering, no interrupt conflicts. 18×12mm, 1.8V–5V logic, 50/60Hz auto-detect.