介紹了基于單片機C8051F020的通用串口適配器的設計與實現方法，即由單片機控制的智能化一對多口收發信號轉換器。通過采用C51對單片機進行編程，控制與RS-232（標準RS-232電平）、RS232(TTL電平)、RS-422接口的數據通信；采用C++ Builder作為開發平臺，通過RS-232接口實現上位機對適配器各個通信端口的控制。
Abstract:
Design and realization of a universal serial port adapter based on the MCU C8051F020 are introduced.The adapter is an intelligent one-to-more receiving and transmitting signal converter controlled by the MCU. By programming the MCU with the language C51,MCU control data communication between the MCU and RS-232(RS-232 level),RS-232(TTL level),RS-422 port; Using C++ Builder as the development plane, by one RS232 port, the upper PC can control each of the communication port of the adapter.
介紹一種基于單片機的多路溫度采集及監控系統，能夠測量6路溫度信號，具有計算機聯網功能，各測量點可以單獨監控和設置，可根據用戶的需求自動控制。測量溫度范圍為-10 ℃～200 ℃，控制方式采用模擬量調壓模式。該系統具有控制精度高、沖擊小等特點。
Abstract:
A temperature collecting and surveillance-controlling system based on sing-chip microcomputer is introduced. It can measure 6 channel signal of the temperature,and it has a function of network connection.The temperature measure points can be monitored and located, it can be controlled automatic according to user’s demand.The temperature range is -10℃ to 200℃.The model of control is adjustable voltage with simulation. It features high precision and little impact.
在需要實時大量輸入漢字的顯示控制處理應用中，利用傳統單片機實現顯示控制的設計方法是較難實現的。帶漢字字庫的液晶模塊的使用使得小容量ROM單片機的大量漢字信息輸入與顯示成為可能。提出了針對漢字字庫編碼的二級索引拼音輸入檢索方法,介紹了以ST7920作為控制器的帶漢字字庫的液晶顯示模塊的接口方法及漢字顯示和控制原理，給出了通用計算機鍵盤在單片機中的串行接口，采用該技術可大大增強單片機的漢字輸入功能。為小容量ROM單片機的大批量漢字信息處理提供了一種漢字輸入解決方案。
Abstract:
It is difficult to realize Chinese characters input method based on the embedded system by using the traditional design method of display control. It is possible to input and display Chinese characters based on the embedded system with the ROM of small content by using the LCD module with Chinese characters.Chinese characters input method of the quadric index recall in allusion to Chinese characters code is brought forward.The interface and the principle of Chinese characters display control based on the LCD module controlled with the ST7920 is introduced too.The serial interface of the computer keyboard in common use and the embedded system is given at the same time. It can enhance the embedded system function of Chinese characters input by using this technology, and provide a kind of Chinese characters input scheme for the embedded system with small capacity ROM.
FEATURES400 MSPS internal clock speedIntegrated 10-bit DAC32-bit tuning wordPhase noise ≤ –120 dBc/Hz @ 1 kHz offset (DAC output)Excellent dynamic performance>75 dB SFDR @ 160 MHz (±100 kHz offset) AOUTSerial I/O control1.8 V power supplySoftware and hardware controlled power-down48-lead TQFP/EP packageSupport for 5 V input levels on most digital inputsPLL REFCLK multiplier (4× to 20×)Internal oscillator; can be driven by a single crystalPhase modulation capabilityMultichip synchronization
基于AT89C52單片機的步進電機控制系統設計
摘 要: 提出了一個由AT89C52單片機控制步進電機的實例。可以通過鍵盤輸入相關數據, 并根據需要, 實時對步進電機工作方式進行設置, 具有實時性和交互性的特點。該系統可應用于步進電機控制的大多數場合。實踐表明, 系統性能優于傳統的步進電機控制器。
關鍵詞: 單片機; 步進電動機; 直流固態繼電器; 實時控制
ABSTRACT: A stepp ing motor control system based on AT89C52 chip microcomputer was described.The data can be inputwith keyboard, and stepp ingmotorwas controlled by these data. According to the demand, users can set the workingmodel of stepp ingmotor in real2time. This system can be widely used in stepp ing motor controlling. The p ractice showed that the performance of this system outdid the tradi-tional stepp ing motor controller.
CAT5110/18/19/23/24/25 linear-taper digitally programmable potentiometers perform the same function as a mechanical potentiometer or a variable resistor. These devices consist of a fixed resistor and a wiper contact with 32-tap points that are digitally controlled through a2-wire up/down serial interface.
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.
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.
The PCA9549 provides eight bits of high speed TTL-compatible bus switching controlledby the I2C-bus. The low ON-state resistance of the switch allows connections to be madewith minimal propagation delay. Any individual A to B channel or combination of channelscan be selected via the I2C-bus, determined by the contents of the programmable Controlregister. When the I2C-bus bit is HIGH (logic 1), the switch is on and data can flow fromPort A to Port B, or vice versa. When the I2C-bus bit is LOW (logic 0), the switch is open,creating a high-impedance state between the two ports, which stops the data flow.An active LOW reset input (RESET) allows the PCA9549 to recover from a situationwhere the I2C-bus is stuck in a LOW state. Pulling the RESET pin LOW resets the I2C-busstate machine and causes all the bits to be open, as does the internal power-on resetfunction.
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.
