Scroll unit is a rotary encoder expansion unit in the form of a scroll wheel. It integrates a 12-pulse through-shaft encoder + button input + WS2812C programmable RGB LED. The built-in STM32F030 microcontroller integrates encoder pulse signal acquisition firmware, allowing users to directly obtain encoder values through I2C reading operations, simplifying complex processes. It is suitable for control scenarios such as scale value control and volume adjustment.