See following threads, RasPi4 support is being worked on but is not yet complete. From an emonPi users perspective a RasPi4 offer little in the way of improvement, the RasPi3B+ is already a performance overkill for Emoncms. The USB-C connection on the RasPi4 will not be used when inside the emonPi enclosure. If you want to help with RasPi4 support, feel free to experiment and join in the conversation on the threads below: