Embedded Wireless Building Intercom System Applied Research

Building conversational system is the essential part in housing construction, and the theme of this paper is a research,which satisfies the demands of building construction.Embedded wireless building conversational system is the combination of embedded technology and wireless communication technology, and it consists of the master and the slave. The master located downstairs carries out the calling of correct user, receives and transmits wireless data, opens unit lock and so on. There are many circuits in hardware, including switch power circuit, microcontroller circuit, wireless communication circuit, ringing circuit, keyboard scanning circuit, audio input/output circuit and relay controlling circuit. The slave is a user terminal which carries out address identification of the master calling, builds or cuts the communication between the master and the slave, and starts the relay. It is similar with the master in composition. In this paper Atmega8 is used as a core to control nRF2401 wireless communication module and other components to actualize the wireless talkback function.AVRGCCIDE is used as the software development platform in this paper, and all of the codes are programmed by C language. Though communication module of nRF2401 is transparent for users, some software communication protocols are still required. This paper puts forward a method about using half-duplex communication to simulate duplex communication with software, which is used in communication based on one point to multi-points.In the end of this paper debugging indexes and methods are proposed, and the testing results are explained. It shows that the system works normally, and can carry out wireless talkback function; quality of conversation is good, the communication distance is about 65m.