以太網和CAN總線應用廣泛，但由于其通信協議不同，兩種總線器件間無法進行數據通信，因此，設計了基于CP2200與C8051F040的以太網總線與CAN總線接口轉換電路，并給出部分相關硬件電路與軟件設計分析。在保證數據完整和協議可靠的前提下，通過握手協議和簡化的以太網協議，不僅實現了以太網數據與CAN數據的轉發，同時還順利的解決了以太網的高速性與CAN的低速率沖突，以及兩者數據包之間的大小不同的矛盾。 Abstract: In the development of actual application， Ethernet and CAN bus are used very extensively. Owing to its various communication protocols， the communicating between two kinds of bus device can’t be carried out. Therefore， in order to solve this problem， the Ethernet-CAN bus interface circuit based on CP2200 and C8051F040 was designed in this paper， and part of the related hardware circuit and software design analysis were given. On the condition of data’s integrity and protocols’reliability， through the handshaking protocols and the simplified the Ethernet protocol， not only the data switching between CAN and Ethernet was realized， but also the differ in velocity and packet size was solved.
上傳時間： 2013-10-15
上傳用戶：Ants
單片機作為一種微型計算機，其內部具有一定的存儲單元（8031除外），但由于其內部存儲單元及端口有限，很多情況下難以滿足實際需求。為此介紹一種新的擴展方法，將數據線與地址線合并使用，通過軟件控制的方法實現數據線與地址線功能的分時轉換，數據線不僅用于傳送數據信號，還可作為地址線、控制線，用于傳送地址信號和控制信號，從而實現單片機與存儲器件的有效連接。以單片機片外256KB數據存儲空間的擴展為例，通過該擴展方法，僅用10個I/O端口便可實現，與傳統的擴展方法相比，可節約8個I/O端口。 Abstract: As a micro-computer,the SCM internal memory has a certain units(except8031),but because of its internal storage units and the ports are limited,in many cases it can not meet the actual demand.So we introduced a new extension method,the data line and address lines combined through software-controlled approach to realize the time-conversion functions of data lines and address lines,so the data lines not only transmited data signals,but also served as address lines and control lines to transmit address signals and control signals,in order to achieve an effective connection of microcontroller and memory chips.Take microcontroller chip with256KB of data storage space expansion as example,through this extension method,with only10I/O ports it was achieved,compared with the traditional extension methods,this method saves8I/O ports.
上傳時間： 2014-12-26
上傳用戶：adada
在深入了解Flash存儲器的基礎上，采用單片機自動檢測存儲器無效塊。主要通過讀取每一塊的第1、第2頁內容，判斷該塊的好壞，并給出具體的實現過程，以及部分關鍵的電路原理圖和C語言程序代碼。該設計最終實現單片機自動檢測Flash壞塊的功能，并通過讀取ID號檢測Flash的性能，同時該設計能夠存儲和讀取1GB數據。 Abstract: On the basis of in-depth understanding the Flash chips，this paper designs a new program which using the SCM to detect the invalid block.Mainly through reading the data of the first and second page to detect the invalid block.Specific implementation procedure was given,and the key circuit schematic diagram and C language program code was introduced.This design achieved the function of using the MCU checks the invalid block finally，and increased the function by reading the ID number of Flash to get the performance of the memory.And the design also can write and read1GB data
上傳時間： 2013-10-25
上傳用戶：taozhihua1314
針對盤山路存在的轉彎盲區，即在轉彎時司機無法得知彎路對面是否有車輛通過，設計一種基于C8051F310的山路轉彎預防警示系統。該系統利用一階濾波算法檢測山路轉彎時是否有車輛通過。運用該算法可增強系統檢測的實時性，提高檢測機動車輛的靈敏度，同時大大減少環境溫度對檢測的干擾。試驗表明該系統能夠正確指示出在山路轉彎時是否有車輛通過，目前該系統已安裝在盤山路上，可大大減少事故的發生率。 Abstract: Aiming at passing hilly road，there is a turn blind spot.Motormen usually do not know if the passing of vehicles pass the road.So a system of defending accident on hilly road is designed,which is based on MCU C8051F310.The sys-tem uses the first-order filter algorithm to detect whether there are passing vehicles.This algorithm enhances the real-time detection and improves the sensitivity of detection vehicles.Meanwhile,it reduces the detection interference of environmen-tal temperature.The experimental results show that this system can exactly indicate if there are passing vehicles.At present,the system has been successfully applied to hilly road.The system can greatly decrease accident.
上傳時間： 2013-10-10
上傳用戶：歸海惜雪
在汽車發動機起動時，若發動機起動后起動機不能及時斷電，將會燒毀起動機或損壞飛輪齒環；若變速器不在空檔位置起動，則起動機的瞬間動力將使汽車位移，還可能引起交通事故和人身安全。為此介紹一種利用NXP P89LPC901單片機控制的汽車起動保護控制器，通過檢測汽車起動開關、變速箱檔位、發動機轉速，實現對汽車發動機起動過程檢測和保護。起動保護控制器在發動機起動過程中通過采用逐個關閉打開負載系統，解決汽車發動機過程中因起動電流大而對汽車電源的沖擊影響,延長了電瓶壽命。 Abstract: When the automotive engine is started, the engine start motor and flywheel gear may be damaged， even traffic accidents and personal safeties may be caused by wrong operation or other factors.In order to ensure the automotive engine can be started normally and safely,it is necessary that the protecting measures and methods are considered in the automotive electrical control system.This paper introduces a kind of the automotive engine starting protect controller based on NXP P89LPC901 MCU.The controller can protect the engine starting process by detecting the starter key switch,transmission stall and engine speed.Through the use of close and open load system,the controller can solve the impact on automotive power because of the high-current load in the process of the automobile engine starting, and extend battery life.
上傳時間： 2013-10-15
上傳用戶：mikesering
為滿足礦井安全生產要求，介紹了一種以AT89C51單片機為主控器，對環境空氣的溫度、有毒易燃氣體的濃度等進行檢測的監控系統。該系統配合外圍電路能實現對上述環境指標的控制并存儲相關數據與上位PC機通信。它采用硬件抗干擾和軟件抗干擾技術，以確保整個系統工作的準確性。 Abstract: In order to meet the needs of mine produce safety，a kind of intellignet mine ambient monotoring and control system based on AT89C51 is introduced.This system can detect the temperature of ambient of mine，the density of poisonous inflammable gas,combined external circuit.With its function part， this system can change above-mentioned elements.
上傳時間： 2013-11-10
上傳用戶：wendy15
為了解決磁放大器性能測試過程中，需要對其供給不同數值恒定電流的問題，設計了一種基于DAC7512和單片機的數控恒流源系統。該系統采用AT89C51作為主控器件，將計算機發送的電流控制字命令轉換為D/A轉換器控制字，通過模擬SPI通信接口，寫D/A控制字到DAC7512，從而控制其輸出相應數字電壓值，經差動縮放電路、電壓/電路變換電路和功率驅動電路，最后輸出恒定電流。實驗結果表明，恒流源輸出電流調節范圍為-45~+45 mA、精度為±0.1 mA，分辨率達0.024 4 mA，具有應用靈活，外圍電路簡單，可靠性高的特點。該數控直流恒流源也可為相關產品的測試系統研發提供參考。 Abstract: In order to solve the need to supply different values constant current for the magnetic amplifier in testing process， numerical control constant current source system was designed based on DAC7512 chip and microcontroller technology. The system used the AT89C51 as the main chip， which can convert the current control word from computer into to D/A control words. And the system wrote D/A control word into the DAC7512 chip to control the output voltage value by the SPI communication interface， which can output corresponding constant current figures by scaling circuit， the V/I converter and power drive circuit. Experimental results show that the current source output current adjustment range is -45~+45mA， accuracy is ± 0.1mA， and resolution ratio is 0.024 4mA
上傳時間： 2014-12-27
上傳用戶：invtnewer
為深入了解基于UC3854A控制的PFC變換器中的動力學特性，研究系統參數變化對變換器中分岔現象的影響，在建立Boost PFC變換器雙閉環數學模型的基礎上，用Matlab軟件對變換器中慢時標分岔及混沌等不穩定現象進行了仿真。在對PFC變換器中慢時標分岔現象仿真的基礎上，分析了系統參數變化對分岔點的影響，并進行了仿真驗證。仿真結果清晰地顯示了輸入整流電壓的幅值變化對系統分岔點的影響。 Abstract: In order to better understand the dynamics characteristic of power factor correction converter based on UC3854A， and make the way that parameters change influences the bifurcation phenomena of the system clearly. The math model of the two closed loop circuits to the Boost PFC （Power Factor Correction） converter controller was built. Then， with the help of Matlab， the simulation for nonlinear phenomena such as chaos and slow-scale bifurcation in the PFC converter was made. Finally the factors that have influence to the phenomenon of bifurcation under slow-scale in PFC converter were analyzed. The simulation results clearly show the parameters change influences the bifurcation point of the system.
上傳時間： 2013-10-17
上傳用戶：杜瑩12345
為降低成本和解決現有膜片鉗放大器系統中PC機的干擾問題，研究了一種基于單片機的膜片鉗放大器小系統。該系統采用ADI公司生產的ADuC841作為控制核心，并且配置相應的液晶顯示模塊LCM3202401。模擬電路部分采用高輸入阻抗的AD8627實現微電流信號的采集，并由后級電路進行信號的放大和電阻電容的補償。它具有硬件電路簡單、體積小、使用方便的特點。既可以單獨作為小系統實現采集和顯示，也可以通過紅外方式和PC機進行通訊，在PC機上進行信號的處理。 Abstract: In order to reduce cost and resolve the interferential problem with PC in existing patch clamp amplifiers, a small patch clamp amplifier system design based on microcontroller is studied. It adopts a new high performance microconverter ADuC841 by the ADI as the control core in the system, configuring a liquid crystal module LCM3202401. In the analog circuit, AD8627 with high input impedance is used to detect the low current，signal magnification, as well as resistance and capacitance compensation are accomplished by subsequent circuits. It has the advantage of simple hardware circuit design, small volume and convenient operation. It can either be used as an independent system to measure and show signal detected or transmit to PC by infrared ray.
上傳時間： 2013-11-06
上傳用戶：yy_cn
為了提高環境參數采集的自動化水平，提升效率，設計了無線傳感器系統。本系統運用了傳感器技術、通信技術和單片機技術，實現了對環境溫度、濕度、光照度以及可燃性氣體濃度等參數的檢測。它能夠實時地與上位機進行無線通信，滿足對環境參數實時監測的要求。 Abstract: In order to increase the degree of automation and improve the efficiency of the environment monitoring parameters，the wireless sensor system was developed.Combining with the technique of sensor,automatic monitoring，communication and single-chip microcomputer，it realized real-time monitoring environment parameters,such as temperature，humidity，illumination，concentration of com- bustible gas and so on.At the same time it can communicate with upper personal computers，satisfy the desire of real-time monitoring.
上傳時間： 2013-11-22
上傳用戶：longlong12345678
