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TLC2543是TI公司的12位串行模數轉換器，使用開關電容逐次逼近技術完成A/D轉換過程。由于是串行輸入結構，能夠節省51系列單片機I/O資源；且價格適中，分辨率較高，因此在儀器儀表中有較為廣泛的應用。 TLC2543的特點 （1）12位分辯率A/D轉換器； （2）在工作溫度范圍內10μs轉換時間； （3）11個模擬輸入通道； （4）3路內置自測試方式； （5）采樣率為66kbps； （6）線性誤差±1LSBmax； （7）有轉換結束輸出EOC； （8）具有單、雙極性輸出； （9）可編程的MSB或LSB前導； （10）可編程輸出數據長度。 TLC2543的引腳排列及說明 TLC2543有兩種封裝形式：DB、DW或N封裝以及FN封裝，這兩種封裝的引腳排列如圖1，引腳說明見表1 TLC2543電路圖和程序欣賞 #include<reg52.h> #include<intrins.h> #define uchar unsigned char #define uint unsigned int sbit clock=P1^0; sbit d_in=P1^1; sbit d_out=P1^2; sbit _cs=P1^3; uchar a1,b1,c1,d1; float sum,sum1; double sum_final1; double sum_final; uchar duan[]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f}; uchar wei[]={0xf7,0xfb,0xfd,0xfe}; void delay(unsigned char b) //50us { unsigned char a; for(;b>0;b--) for(a=22;a>0;a--); } void display(uchar a,uchar b,uchar c,uchar d) { P0=duan[a]|0x80; P2=wei[0]; delay(5); P2=0xff; P0=duan[b]; P2=wei[1]; delay(5); P2=0xff; P0=duan[c]; P2=wei[2]; delay(5); P2=0xff; P0=duan[d]; P2=wei[3]; delay(5); P2=0xff; } uint read(uchar port) { uchar i,al=0,ah=0; unsigned long ad; clock=0; _cs=0; port<<=4; for(i=0;i<4;i++) { d_in=port&0x80; clock=1; clock=0; port<<=1; } d_in=0; for(i=0;i<8;i++) { clock=1; clock=0; } _cs=1; delay(5); _cs=0; for(i=0;i<4;i++) { clock=1; ah<<=1; if(d_out)ah|=0x01; clock=0; } for(i=0;i<8;i++) { clock=1; al<<=1; if(d_out) al|=0x01; clock=0; } _cs=1; ad=(uint)ah; ad<<=8; ad|=al; return(ad); } void main() { uchar j; sum=0;sum1=0; sum_final=0; sum_final1=0; while(1) { for(j=0;j<128;j++) { sum1+=read(1); display(a1,b1,c1,d1); } sum=sum1/128; sum1=0; sum_final1=(sum/4095)*5; sum_final=sum_final1*1000; a1=(int)sum_final/1000; b1=(int)sum_final%1000/100; c1=(int)sum_final%1000%100/10; d1=(int)sum_final%10; display(a1,b1,c1,d1); } }
上傳時間： 2013-11-19
上傳用戶：shen1230
在理論分析循環碼編碼和譯碼基本原理的基礎上，提出了基于單片機系統的(24，16)循環碼軟件實現編碼、譯碼的方案。仿真結果表明(24，16)循環碼能有效地克服來自通訊信道的干擾，保證數據通信的可靠及系統的穩定，使誤碼率大幅度降低。本論文對(24，16)循環碼的研究結果表明，可以有效地降低錯誤概率和提高系統的吞吐量，實現糾錯僅需要在接收端增加有限的存儲空間和計算復雜度，具有一定的實用價值。 Abstract: Based on analyzing the theory of encoding and decoding of cyclic code， this paper showed the schemes of encoding and decoding of(24，16)cyclic code by the software and based on microcontroller. Simulation results show that using (24，16) cyclic codes can effectively overcome the interference from communication channel， ensure the reliability and stability of data communication systems， and reduce the bit error rate greatly. The results of this paper show that by using the (24，16) cyclic code， the error rate can be reduced and the system throughput can be improved. Meanwhile， the system only needs to enlarge limited storage space and computation the complexity at the receiving end to realize error correction. Thus the (24，16) cyclic code has a practical value.
上傳時間： 2013-11-09
上傳用戶：gaoliangncepu
利用單片機具有的智能程序控制的特點，設計了基于STC89C52單片機的"二極管特性測試器"，可對二極管一般特性進行快速測試。通過穩定線性電流源給二極管加載恒定電流，然后由高精度模數轉換器測試其壓降，以此為基礎可判斷二極管好壞、檢測二極管極性和測試二極管伏安特性等，避免了用萬用表測試只能測得極性而不知其特性這一缺點。可用于電子設計制作過程中對二極管進行快速測試，以確定被測二極管是否滿足電路的設計要求。 Abstract: By making good use of the intelligent control function of the Micro Controller Unit (MCU)， the diode trait tester was designed based on the STC89C52，which could be used to test the trait of a diode rapidly. By loading constant current to diode through the stable linear current source， and measuring the voltage drop of the diode by high-precision analogue-to-digital converter (ADC)， it can judge whether the diode is good or not， distinguish the polarity of the diode， and test the trait that the diode， which can avoid the fault of using a multimeter can only measure the polarity but not the trait. This device can be used to test the trait of a diode quickly，and to make sure that whether a diode can be used in the electronic design or not.
上傳時間： 2013-11-13
上傳用戶：assef
為解決我國水位監測野外條件下長期無人看守的問題，研制開發了基于MSP430單片機的智能水位計。從其組成到各功能分別進行了詳細的介紹，該智能水位計不僅實現了水位數據的實時監測、記錄和定期采集等多種工作模式，而且提高了水位監測精度，實現了水位監測的智能化。 Abstract: In order to solve the problems of long-term unmanned observation in the field water monitoring，an intelligence water-level meter based on MSP430 is developed composition and every function moduce of the water level meter was introduced in detail. It not only realizes water level data collection and storage， regularly gathering and so on， but also improves the water-level precision ， finally realizes the intelligence.
上傳時間： 2013-11-17
上傳用戶：417313137
The MAX9257/MAX9258 programmable serializer/deserializer (SerDes) devices transfer both video data and control signals over the same twisted-pair cable. However, control data can only be transmitted during the vertical blank time, which is indicated by the control-channel-enabled output (CCEN) signal. The electronic control unit (ECU) firmware designer needs to know how quickly to respond to the CCEN signal before it times out and how to calculate this duration. This application note describes how to calculate the duration of the CCEN for the MAX9257/MAX9258 SerDes chipset. The calculation is based on STO timeout, clock frequency, and UART bit timing. The CCEN duration is programmable and can be closed if not in use.
上傳時間： 2014-01-24
上傳用戶：xingisme
現有基于MAX7219芯片的數碼管驅動電路只適用于小尺寸LED，為擴展其使用范圍，在介紹動態顯示芯片MAX7219功能的基礎上，提出了一個基于該芯片的8位高亮度8英寸數碼管驅動電路。電路保留了MAX7219芯片的功能強大、編程簡單等優點，通過74LS273鎖存器和ULN2803達林頓驅動器，實現了對任意大尺寸數碼管提供較高電壓和電流驅動的靜態顯示，并亮度可調。 Abstract: The existing display-driving circuit based on MAX7219 was only applicable to small-size LED. To expand its use, based on the function introduction of dynamic display chip MAX7219, a display-driving circuit for high-brightness 8-bit LED with the size of 8-inch was proposed. The advantages of MAX7219 were retained, such as powerful function and simple programming. Static display with adjustable brightness for large-size LED with higher voltage and current was achieved with the help of 74LS273 and ULN2803.
上傳時間： 2013-10-23
上傳用戶：31633073
為解決當前計算機串行通訊接口只有USB，難以滿足舊型號設備或某些單片機要求RS232通訊的問題，設計出兩款RS232/USB電路。采用CH341A與MAX223集成電路芯片構建標準9線RS232/USB通用接口轉換器，無需編程。采用CH341A與PIC16F877A構建單片機與計算機之間的USB通訊電路，軟件遵循RS232通訊協議，硬件進行電平轉換。實際使用表明，這兩款產品與計算機端Windows 操作系統下的串口應用程序完全兼容，且通訊過程中無握手失敗現象。 Abstract: To solve the problem that current computer serial communication only with USB interface can not satisfy with the old type equipments or MCU to communicate with RS232， two kinds of RS232/USB circuit were designed.CH341A and MAX223 integrated circuit chips were used to create a standard 9-line RS232/USB universal interface convertor without programme. CH341A and PIC16F877A chips were adopted to build the USB communication circuit between computers and MCU. The software follows RS232 communication protocol， and the hardware converts electrical levels. Actual practices indicate that the two manufactures are compatible with serial application program of Windows operation system completely，and get avoid of handshake lost.
上傳時間： 2013-11-03
上傳用戶：siying
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
針對目前汽車追尾事件頻發問題，提出一種防汽車車前和車后追尾的安全裝置設計。該設計以高性能、低功耗的8位AVR微處理器ATmega8L為核心，結合霍爾式車速傳感器、激光雷達測距裝置和MMA7260QT加速度傳感器，能夠兼顧車前和車后，摒棄以往設計中只考慮車前或車后單一性缺點，尤其適用于高速、夜晚或新手行車。 Abstract: Aiming at the high frequency of vehicle rear-end collision，a safe device design of anti-vehicle rear-end collision is presented.In the design，the high-performance，low-power8-bit AVR microprocessor ATmega8L is utilized as a core combined with Hall-type speed sensor，laser-radar ranging devices and the acceleration sensor MMA7260QT.The design considers both the front and back of a car，and overcomes the drawbacks of former designs in which only the front or the back of the car is considered，so it is especially suitable for high-speed，night or the beginner’s driving.
上傳時間： 2013-10-14
上傳用戶：GavinNeko
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