針對目前使用的RS232接口數字化B超鍵盤存在PC主機啟動時不能設置BIOS，提出一種PS2鍵盤的設計方法。基于W78E052D單片機，采用8通道串行A/D轉換器設計了8個TGC電位器信息采集電路，電位器位置信息以鍵盤掃描碼序列形式發送，正交編碼器信號通過XC9536XL轉換為單片機可接收的中斷信號，軟件接收到中斷信息后等效處理成按鍵。結果表明，在滿足開機可設置BIOS同時，又可實現超聲特有功能，不需要專門設計驅動程序，接口簡單，成本低。 Abstract: Aiming at the problem of the digital ultrasonic diagnostic imaging system keyboard with RS232 interface currently used couldn?蒺t set the BIOS when the PC boot， this paper proposed a design method of PS2 keyboards. Based on W78E052D microcontroller，designed eight TGC potentiometers information acquisition circuit with 8-channel serial A/D converter， potentiometer position information sent Out with keyboard scan code sequentially.The control circuit based on XC9536 CPLD is used for converting the mechanical actions of the encoders into the signals that can be identified by the MCU， software received interrupt information and equivalently treatmented as key. The results show that the BIOS can be set to meet the boot， ultrasound specific functionality can be achieved at the same time， it does not require specially designed driver，the interface is simple and low cost.
上傳時間： 2013-10-10
上傳用戶：asdfasdfd
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
提出一種基于凌陽單片機的步進電機加減速的控制方法。采用凌陽科技推出的16位結構工控單片機SPMC75F2413A為控制器，由Allegro公司生產的兩相步進電機專用驅動器件SLA7042M構成步進電機的驅動電路，在傳統的3段直線加減速控制算法基礎上增加至7段S形曲線加減速過程，控制步進電機的啟動和停止。實驗結果表明，該控制方法克服了直線加減速中不連續、易造成系統沖擊的問題，整個系統實現柔性控制，電機啟動、停止連續性能提高30%。 Abstract: The method of controlled stepping motor is referred based on SPMC75F2413A MCU， which adopts the 16 knots SPMC75F2413A MCU as the controller. The special-purpose actuation chip SLA7042M of two stepping motor produced by Allegro Corporation constituted to actuation electric circuit. The purpose of increasing to seven section of S shape curve based on the traditional three sections of straight line is to control the start and stop process of stepping motor. The experimental results show that the control method solves easy to pull-Out and overshot problems. The overall system realizes flexible control， and the performance of motor start or stop continuity is increased 30%
上傳時間： 2013-12-08
上傳用戶：jiangfire
電路圖非常簡單，主要的問題不在于電路，電路用一上午的時間就都搞定了，剩下的就是程序問題。為了美觀要達到的目的是LED燈要不斷地閃爍，同時這LED中P2口控制的都是綠色的，P1口控制的都是紅色的，這樣就容易編程了。起初在主函數中直接對LED燈控制并且檢測HS0038的電位變化但是始終檢測不到，后來發現延時太長在延時的過程中掩蓋了對HS0038的檢測。所以縮小延時，但是無論怎么減小對于檢測的時間來講都是太大的。最后想到了用單片機的外部中斷的功能，所以將HS0038的Out接到P3.3口用外部中斷1 將檢測放在終端函數中最后解決了問題，實現檢測和LED閃爍的功能。
上傳時間： 2013-10-18
上傳用戶：stewart·
NEC 78K系列單片機安全性概覽 78K系列單片機沒有program read-Out 功能，使用任何編程器都無法讀出程序存儲區內的數據。
上傳時間： 2013-11-19
上傳用戶：menggesimida
1、 支持USB 1.1通訊協議；2、 支持高速（Full Speed、12Mbps ）和低速（Low Speed、1.5Mbps ）傳輸；3、 6MHz晶體，鎖相環PLL振蕩器提供高速、低速所需時鐘源；4、 支持3個端口（endpoint），可獨立編程為IN 或 Out端口。5、 PS/2：支持PS/2協議（eg.鼠標），與USB復用。
上傳時間： 2013-11-03
上傳用戶：hbsunhui
The PCA9540B is a 1-of-2 bidirectional translating multiplexer, controlled via the I2C-bus.The SCL/SDA upstream pair fans Out to two SCx/SDx downstream pairs, or channels.Only one SCx/SDx channel is selected at a time, determined by the contents of theprogrammable control register.
上傳時間： 2014-12-28
上傳用戶：nshark
The PCA9542A is a 1-of-2 bidirectional translating multiplexer, controlled via the I2C-bus.The SCL/SDA upstream pair fans Out to two SCx/SDx downstream pairs, or channels.Only one SCx/SDx channel is selected at a time, determined by the contents of theprogrammable control register. Two interrupt inputs, INT0 and INT1, one for each of theSCx/SDx downstream pairs, are provided. One interrupt Output, INT, which acts as anAND of the two interrupt inputs, is provided.
上傳時間： 2013-12-07
上傳用戶：europa_lin
The PCA9546A is a quad bidirectional translating switch controlled via the I2C-bus. TheSCL/SDA upstream pair fans Out to four downstream pairs, or channels. Any individualSCx/SDx channel or combination of channels can be selected, determined by thecontents of the programmable control register.
上傳時間： 2013-11-16
上傳用戶：cc1915
The PCA9547 is an octal bidirectional translating multiplexer controlled by the I2C-bus.The SCL/SDA upstream pair fans Out to eight downstream pairs, or channels. Only oneSCx/SDx channel can be selected at a time, determined by the contents of theprogrammable control register. The device powers up with Channel 0 connected, allowingimmediate communication between the master and downstream devices on that channel.
上傳時間： 2014-12-28
上傳用戶：270189020
