單片機多機通信實現(xiàn)_畢業(yè)論文


摘要：目前，單片機在多機通信領域應用很廣。但研究最多的是上位機與下位機的通信及多單片機構成的主從式多機通信系統(tǒng)。本文重點研究了多單片機的平權式多機通信，使各單片機有相同的權限。
本文從平權式多機通信協(xié)議入手，首先設計了具體平權式多機通信協(xié)議;主機通信用按鍵控制，模擬實際應用中的觸發(fā)信號輸入。對于1號單片機，還可通過液晶實時顯示工作狀態(tài)，初始為主機。在不需置其他單片機為主機的情形下，本多機通信系統(tǒng)可以作為主從式多機通信系統(tǒng)。從機通信模式通過串口中斷觸發(fā)啟動，通信結束即恢復之前的從機狀態(tài)。通信過程中，主機先發(fā)送尋址的從機號，待從機響應后開始通信。通信結束后，主機發(fā)送自己的主機號，告知從機。然后從機發(fā)給主機校驗字節(jié)數(shù)據(jù)，主機檢驗錯誤，檢驗無誤后，作出響應，1號單片機液晶會顯示，2號和3號單片機收發(fā)數(shù)據(jù)無誤后會使LED指示燈亮起。其外，本文研究了可切換雙向接口的實現(xiàn)方法。通過用單片機的一個引腳控制單片機的串口的連接方式，使其工作在主機模式或從機模式。
本研究已經(jīng)仿真通過，真實可行。具有一定的檢錯能力，串行通信的比特率是9600bit/s，通信速度較快，且可靠性高。本研究通過硬件電路解決了通信過程中多單片機爭用主機權的問題。

關鍵詞：單片機；多機通信；平權；AT89S52

Realization of many SCM communication
Abstract：At present, the single chip multi-machine communication in a wide field of applications. However, the most studied is the host computer and lower computer communications and multi-chip microprocessor master-slave multi-machine communication system. This paper focuses on a number of single chip multi-machine communication affirmative, so that the MCU has the same permissions.
   The paper machine from the multi-level communication protocol of the right to start with, first, the specific communication protocol. Host Communication button control, the practical application of simulation in the trigger signal input. For the No. 1 microcontroller, but also through the LCD display working status, the initial for the host. No other single chip set in the case of the host, the multi-machine communication system can be used as master-slave multi-machine communication system. Communication mode from the machine through the serial port interrupt triggering, communication before the end of the recovery from the machine state. Communication process, the host sends the address number from the machine until the response from the plane after communications. After communication, the host sends its own host number, informed from the machines. And then distributed to the host from the machine check bytes of data, the host test error, test and proved correct response, 1 single chip LCD displays, 2 and 3, after the MCU will send and receive data correct LED light is on. Besides, this paper, bi-directional switch implementation of the interface methods. Through the use of microcomputer control of a microcontroller pin serial port connection, to work in master mode or slave mode.
This study has been simulated by the real feasible. Have some error detection capability, the bit rate of serial communication 9600bit / s, communication speed, and reliability. In this study, the hardware circuit through the communication process to resolve the contention over the host microcontroller over the issue.
Key words：：SCM；Multi-machine communication；Equal rights； AT89S52
 
目錄
1 緒論 1
1.1 論文研究的背景與意義 1
1.2 單片機多機通信領域的歷史及國內(nèi)外發(fā)展現(xiàn)狀 1
1.3 本論文的研究內(nèi)容 2
2 單片機多機通信理論及方案選擇 3
2.1 單片機串口通信 3
2.2 單片機多機通信方案選擇 5
2.3 微處理器的選擇 5
2.4 液晶LCD1602介紹 9
3 單片機多機通信協(xié)議設計 15
4 硬件電路設計 16
4.1 單片機最小系統(tǒng)的設計 16
4.2 矩陣鍵盤電路設計 17
4.3 液晶顯示電路設計 18
4.4 可切換接口電路設計 19
4.5  2號與3號單片機按鍵電路設計 23
4.6  LED顯示電路設計 23
4.7  主機權分配電路設計 24
4.8  電源電路設計 28
5 軟件設計 29
5.1  多機通信協(xié)議的算法設計 29
5.2  鍵盤程序設計 32
5.3  系統(tǒng)初始化程序設計 35
6 結論 35
參考文獻 36
致謝 37
附錄1：1號單片機電路原理圖 38
附錄2：2號單片機電路原理圖 39
附錄3：3號單片機電路原理圖 39
附錄4：仿真電路圖 41
附錄5：源程序： 42