基于51单片机的多功能门铃的设计外文资料翻译

基于51单片机的多功能门铃的设计外文资料翻译内容摘要：

a stable and reliable quality, clear voice and fairly practical value. Second: Features At present domestic doorbell has been a lot of visualization products, mainstream product is wired, oneway voice and Simulation. Visual Round wireless doorbell system bines puter technology, wireless munications and digital signal processing technology used in highfrequency wireless transmitter receiver, installation without cabling, would not undermine the effectiveness decoration. Visual Round wireless doorbell system is the next generation of electronic security systems, modern gardens, Villa, Villa ideal security device. Family in the living room, through the screen to see images, voice speaking, remote understanding of the situation outside, accurate judgement visit in the capacity of the reception to decide whether to open the door to protect the family39。 s personal and property safety. The system uses modular hybrid technology, digital voice, video simulation, the future is alldigital wireless doorbell system visualization talk of a transition, the system39。 s main features are: (1) GHz, 900MHz highfrequency signal transmission. (2)In the 60 m clearly within the scope of stable transmission audio and video signals at a barrier such as distance is 30m. (3)If on the doorbell, Ding Dong Sound hints open automatically monitor screen (4)Wireless unlock, and control of the electric door lock control. (5)Indoor Wireless proactively monitor. (6)Delay shut down automatically monitoring system. (7)Wireless transmission, the receiver can easily be placed, easy installation. (8)Wireless fullduplex voice munication. The system is posed of two parts: part of indoor and outdoor part. Visual Round wireless doorbell system uses fullduplex digital wireless voice programmes, indoor and outdoor machines are corresponding to the four basic modules, including A / D / A modules from voice codec chip MC145481 pleted, the speech signal processing module from the CPLD digital voice signals as well as a package of reconciliation package synchronization, thereby enhancing antijamming capability. wireless transmit / receive modules to deal with the digital signal modulation and demodulation, it suitable for wireless channel transmission. Third: Voice transmission processing Although voice processing digital signal transmission than analog signals have great advantages, but digital signal analog signal difficult than receiving, processing requirements more stringent than the analog signal, with the development of society, wireless munication equipment widely used, resulting in increased electromagic interference, and advances in technology enabling wirel。