基于单片机的电子音乐门铃外文参考

1、Visual Round wireless doorbell in the voice communications system design and implementationFirst:IntroductionMicroelectronics technology, wireless technology and network technology for the development of modern people living environment of security, facilitate the provision of a strong technical sup

2、port，This presents a smart area for the safety of the new wireless doorbell system visualization Round, On the systems overall structure and working principle and the key technology full-duplex digital voice communications for the design and realization of，Analysis of the digital transmission of voi

3、ce processing, a frame structure on the design and realization of the CPLD in a wireless doorbell system visualization Round-frame synchronization . Finally, the prototype system by the field test, stable performance, reliable, clear voice, has good practical value.The development of electronic, wir

4、eless and network technology provides the strong technical support for security and convenience of modern residential quarters. In this paper, we introduce a new style wireless visual inter-conversation doorbell system, which is used in the intelligent residential quarters. Then explains the structu

5、re of this system, and its full-duplex digital voice communication is designed and implemented. We emphasize the digital voice process in transmission, and discuss the design of the structure of frame, and the frame synchronization realized in CPLD. Finally, the test result shows a stable and reliab

6、le quality, clear voice and fairly practical value.Second:FeaturesAt present domestic doorbell has been a lot of visualization products, mainstream product is wired, one-way voice and Simulation. Visual Round wireless doorbell system combines computer technology, wireless communications and digital

7、signal processing technology used in high-frequency 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

8、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 familys personal and property safety. The system uses modula

9、r hybrid technology, digital voice, video simulation, the future is all-digital wireless doorbell system visualization talk of a transition, the systems main features are:(1)2.4 GHz, 900MHz high-frequency signal transmission.(2)In the 60 m clearly within the scope of stable transmission audio and vi

10、deo 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 trans

11、mission, the receiver can easily be placed, easy installation.(8)Wireless full-duplex voice communication.The system is composed of two parts: part of indoor and outdoor part. Visual Round wireless doorbell system uses full-duplex digital wireless voice programmes, indoor and outdoor machines are co

12、rresponding to the four basic modules, including A / D / A modules from voice codec chip MC completed, the speech signal processing module from the CPLD digital voice signals as well as a package of reconciliation package synchronization, thereby enhancing anti-jamming capability. wireless transmit

13、/ receive modules to deal with the digital signal modulation and demodulation, it suitable for wireless channel transmission.Third:Voice transmission processingAlthough voice processing digital signal transmission than analog signals have great advantages, but digital signal analog signal difficult

14、than receiving, processing requirements more stringent than the analog signal, with the development of society, wireless communication equipment widely used, resulting in increased electromagnetic interference, and advances in technology enabling wireless receiver continuously improve receiver sensi

15、tivity, wireless receiver in the corresponding sent equipment will not be there when the output data demodulation. Wireless communications must be according to data frame transmission of data packet, and must be adopted and reliable way to ensure the frame synchronization of data from the chaos of t

16、he data frame will be legitimate identified. Frame synchronization can be used in synchronous or synchronous code. Synchronization of the relatively high hardware requirements to achieve more difficult, it seldom use more than a code synchronization. Synchronous Code should ensure that the choice of

17、 code and data re-synchronization code probability as low as possible, so as to the general application of the HS .That the need for re-design code to escape if a frame set up between the timer and overtime provisions of the transfer agreement in the data frame length, frame synchronization code can

18、 be arbitrary choice, the general choice 0xAA, 0x55, such as 0 - 1 uniform Distribution of data, and in order to improve reliability, often the choice of multi-byte frame synchronization code, such as 0xAA 0xBB (2-byte frame synchronization code).To establish stable communication, a standard wireles

19、s data transmission frame should include at least the following parts:(1) Jumping code: in the receiving establishment phase, providing reception threshold level, its length and hardware relevant data, wireless doorbell system visualization Talkback used in the x99 is 0.(2) redundant code: According

20、 to experience, usually adopts a 0xff or 0xff, 0x66 results were relatively good, and the establishment of communication to correct errors arising from the phase-out-of-step serial receiver, in the slow speed (19200 bps), the two often use L-redundant code is not adopted in the design.(3)Synchronous

21、 Code: used for frame synchronization, data transfer and use of relatively low-bit-rate code word, and in order to improve reliability, and a 2-byte or 2 bytes above synchronous code words such as 0xaa 0xbb. Visual Round wireless doorbell system is used in the 0xCCCCCC.(4)Data: users want to transfe

22、r data to improve the reliability of communications, the proposed Manchester encoding the data or using DPCM send, and data validation. Manchester encoding or used in the DPCM transmitted, the length of the data generally should not exceed 256 bytes; on the contrary, should not exceed 64 bytes. But

23、speaking in the wireless doorbell visual system, digital voice wireless transmitter module maximum data transmission rate of 76.8 kbps, but the voice from the A / D chip from 64 kbps data there, as affected by the CPLD antenna bandwidth capacity and launch two factors constraints, we do not have to

24、deal with complicated coding. 0 x99 precursor for which code for the initial bit synchronization and receive state machine reset, 0xCCCCCC data frame synchronization code, frame synchronization for eight yards behind-control code. Visual Round wireless doorbell system in the control code number of s

25、mall, indoor to outdoor is three, has taken the initiative to monitor the lock, removable hang up. Outdoor to indoor control signal only a call button, we will design the frame synchronization byte code for the control signal transmission in the back to keep up with the control signal in bytes of vo

26、ice and data units.Software using top-down design methodology, a total of five documents: the top-level documents were, transmit modules accept modules, digital phase-locked loop and frame state machine. Top-level document for the system clock with a 2048 kHz voice codec interface chip MC, including

27、 sending and receiving of two functional modules L module which is sent to send data in the original data before adding header, voice communications frame 0x99 first, 0xCC, 0xCC, 0xCC, followed by the control signal byte, in bytes of voice and data units for L receiver module is to detect and contro

28、l the speech signal, the relatively complex, including digital phase-locked loop and frame status two-state, if detected 0xCC, 0 from the state into a state if a byte is 0xCC from a state into two states, or else to return to state 0; If the first three bytes or 0xCC from entering the state 2 3 stat

29、e into synchronous state, or to return to state 0 which DPLL is a bit synchronization.As voice signals are relatively weak in general, according to M u/A code of law, may be even longer, 1, so that the receiver can not extract the correct information in sync, so we carried out a simple voice and dat

30、a handling, even if 1 is greater than the number eight, an eighth reverse, namely, 1 to 0. As one of the quantitative data sampling points last a minimum weights, this will not deal with the impact of.Last:Concluding remarksBased on the visual-speaking wireless doorbell system, and its two-way voice

31、 communications for the design and realization, it is has been tested and empty distance of 60 m, 30 m to obstructions, clear voice L test results show that the design of a performance stable and reliable, voice clear, simple design, and other features, the value of L practical course of the program

32、me in this paper on the properties have yet to be improved, then we have to do the work is the image of real-time digital information transmission, thus achieving all-digital wireless Visualization Round doorbell system.可视对讲门铃系统中语音通信的设计与实现一、引言微电子技术、无线技术和网络技术的发展为现代人们居住环境的安全、方便提供了有力的技术支撑，由此介绍了一种用于智能小区

33、安全的新型的无线可视对讲门铃系统，阐述了该系统的总体结构和工作原理，并对其中的关键技术全双工数字语音通信进行了设计和实现，分析了数字语音在传输中的处理，讨论了帧结构的设计，并在CPLD 中实现了无线可视对讲门铃系统的帧同步，最后对所做的样机系统进行了无对所做的样机系统进行了实地测试，性能稳定、可靠，语音清晰，具有很好的实用价值。电子贸易的发展，无线和网络技术为安全性与方便性的现代住宅小区提供了强有力的技术支撑。在这篇文章中，我们引入一个新的作风，无线视觉跨交谈门铃系统，它可以用来在智能化住宅小区。我们引入一个新的作风，无线视觉跨交谈门铃系统，它可以用来在智能化住宅小区。然后解释了结构这个制度，

34、它的全部全双工数字语音通信的设计和实施。我们强调在传送数字化语音过程中，并讨论了结构设计的框架，以及帧同步实现的CPLD 。最后，测试结果表明，一个稳定和可靠的质量，清晰的语音和相当的实用价值。随着微电子技术、无线技术和网络技术的飞速发展，人们对于居住环境的安全、方便提出了越来越高的要求，因此智能化小区随之出现L随着改革开放的深入和市场经济的迅速发展，城市流动人口大量增加，带来诸多不安定因素，可视门铃等安全防范装置得到了广泛应用。目前国内已经有很多可视门铃方面的产品，主流产品是有线方式，单向语音且模拟。无线可视对讲门铃系统结合微机技术、无线通信技术和数字信号处理技术，采用在高频段无线发送接收，

35、安装时无需布线，不会破坏装修效果。本文主要针对无线可视对讲门铃系统中的关键技术语音通信进行设计和实现。二、功能特点无线可视对讲门铃系统的功能特点无线可视对讲门铃系统是新一代电子安全防范系统，是现代花园、山庄、别墅理想的安全防范装置。家人可以在室内，通过屏幕看图像、语音对讲，远距离了解门外的情况，准确判断来访者的身份，决定是否开门接待，保障家庭的人身和财产安全L该系统采用模数混合技术，即语音数字，视频模拟，是将来全数字无线可视对讲门铃系统的一个过渡，该统的主要功能特点有:(1) 2. 4 GHz，900MHz 高频信号传送。(2) 能在60 m 范围以内清晰地传送稳定的音、视频信号; 如隔有障碍

36、物，距离则为30 m 。(3) 如有人按门铃，则有“叮咚”声提示并自动打开监视画面。(4) 无线开锁，控制门口的电控锁。(5) 室内机无线主动监视。(6) 延时工作，自动关闭监控系统。(7) 无线传送，可随意放置接收机，安装方便。(8) 无线全双工语音通信。该系统由两部分组成: 室内机部分和室外机部分室内机主要由语音芯片、数字信号处理模块、单片机AT89C51，显示屏和2.4G 接收模块及无线收发模块等组成。无线可视对讲门铃系统采用无线全双工数字语音方案，室内室外机都由四个相对应的基本模块组成，其中A/D/A 模块由语音编解码芯片MC 完成，语音信号处理模块由CPLD 对数字语音信号进行打包和

37、解包以及同步处理，从而提高抗干扰能力。无线发射/接收模块对处理后的数字信号进行调制和解调，使其适合无线信道的传输。三、语音传输处理语音传输处理虽然数字信号比模拟信号有很大的优点，但是数字信号比模拟信号难于接收，处理的要求比模拟信号更为严格。随着社会的发展，无线通信设备的广泛使用，导致电磁干扰加剧；而技术的进步使无线接收机的接收灵敏度不断提高，所以无线接收机在相应的发送设备不作时也会有数据解调输出。无线通信中必须按数据帧分组传输数据，并且必须采可靠的帧同步方式来保证从混乱的数据中将合法的数据帧识别出来。 帧同步可以采用位同步或码同步。位同步对硬件设备要求比较高，实现比较困难，一般很少使用而多采用码同步。同步码的选择应该保证同步码与数据重码概率尽可能低，以便在一般的应用中，协议不需要进行重码的转义设计; 如果帧之间设置有超时定时器并且传输协议规定了帧数据长度，那么帧同步码则可以任意选择，一般选择0xAA，0x55之类0- 1均匀分布的数据，并且为了提高可靠性，往往选择多字节的帧同步码，比如0xAA，0xBB (两字节帧同步码)。要建立稳定的通信，一个标准的无线数据传输帧应该至少包括以下部分：(1) 前导码：用在接收建立阶段，提供接收的门限电平，其数据长度与硬件有关，无线