Behringer Ultradrive is one of the world's best selling digital loudspeaker management systems. For over 15 years many have considered it to be the bang for the buck in the price range. This project plugs in to the RS232 port of the device and enables it to be controlled using a web browser. No wifi router or internet connection needed, no applications to install. All software and hardware is released under permissive licenses. You can try out a demo ui here http://duinodcx.herokuapp.com.