FreeMDU

FreeMDU is an open-source toolkit that provides both hardware and software solutions for communicating with Miele appliances through their often overlooked optical diagnostic interface, effectively offering an accessible alternative to the proprietary Miele Diagnostic Utility used by service technicians. This project includes reverse-engineered protocol support, a terminal user interface for diagnostics, and firmware that can act as a USB-UART bridge or standalone communication adapter for home automation systems. Developers and tinkerers can use FreeMDU to read diagnostic codes, monitor appliance internal states, and even integrate device feedback into platforms like Home Assistant using MQTT, making it valuable for repair, automation, and monitoring applications. The repository’s components are split into multiple subprojects.