Implementation of local area digital audio broadcasting system upon I2C network

Conventionally, local area audio broadcasting systems use analog channels for voice transmission. They are constructed with one main voice transmitter and many loudspeakers. The inherent disadvantages lie in the difficulties to make individual or restricted area communication without additional complex switching box; besides, a pre-planed wiring are necessary, which makes any on-line re-distribution almost impossible. To overcome above problems, the system developed here uses digital voice transmission upon I2C network. This system has many advantages: enhance the voice quality of broadcasting, encrypts the voice data for secret communication and reduce the overall system cost for construction and maintenance. Other devices such as sensors and actuators can be added or removed from this I2C bus easily; therefore a cost effective network of communication with security/monitoring functions for buildings, plants or communities can be built.