M5Stack M129 HMI Interface Module is an interactive module that provides a rotary encoder, two input buttons, and 2 LED indicators. This module uses STM32F030 as the acquisition and communication MCU and also communicates with the M5 host through I2C. The M129 HMI interface module offers a 500mAh built-in lithium battery and port C and port B interfaces on the module. This module features Arduino and UIFlow programming platforms and human-machine interaction (rotary encoder, two input buttons, and two LED indicator lights). The M129 HMI interface module operates at 0°C to 40°C operating temperature range and 5V supply voltage. This module is ideally used in industrial control, embedded systems, and smart home applications.