It was undertaken between 2018 and 2019 and the design of this system is intended to meet the requirements of harsh and critical interference environments. The system’s purpose is to collect all the audio signals from various sources, multiplex them and set gains and impedance for different output channels for further transmission and usage. It involved multiple boards such as Power Supply Board, DSP Processor Board, Mother Board and Interface Board. Our engineers used system architecture design, schematics design, layout design and firmware development to deliver a solution that meets the client’s requirements. The system also includes a full-duplex communication feature and multiple communication interfaces such as IIC, RS232, RS485, SAI and SPI.