GM25516 is a type of smart controller developed by Wodeyijia. It is based on the Microchip 8-bit PIC18F microcontroller and is capable of controlling up to 16 individual devices. The GM25516 is designed for both residential and commercial applications and is suitable for a wide range of applications, including motor control, monitoring, lighting control, HVAC, security, and energy management. It has a range of features, such as PWM, boost, dimming, and synchronization. It offers I/O expansion, which allows to expand the system with additional devices, and supports bootloading, which enables faster and easier updating of firmware.