为解决当前计算机串行通讯接口只有USB，难以满足旧型号设备或某些单片机要求RS232通讯的问题，设计出两款RS232/USB电路。采用CH341A与MAX223集成电路芯片构建标准9线RS232/USB通用接口转换器，无需编程。采用CH341A与PIC16F877A构建单片机与计算机之间的USB通讯电路，软件遵循RS232通讯协议，硬件进行电平转换。实际使用表明，这两款产品与计算机端Windows 操作系统下的串口应用程序完全兼容，且通讯过程中无握手失败现象。 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.
上传时间： 2013-11-03
上传用户：siying
Digitemp Jr. is a device that is designed to measure and repOrt ambient temperature. When connected to an RS-232 pOrt on any PC, it will periodically measure and repOrt in ASCII fOrm the ambient temperature in degrees Celsius. These temperature readings can be monitOred with any terminal program. If the terminal program suppOrts capture to disk, the temperature readings can be saved to disk fOr further analysis with a spreadsheet program Or other data analysis tool. The simple ASCII output fOrmat of Digitemp Jr. makes it relatively easy to write custom software fOr receiving, recOrding, and analyzing ambient temperature data. Best of all, Digitemp Jr. requires no external power supplies Or batteries. It is powered directly by the RS-232 pOrt.
上传时间： 2013-10-20
上传用户：Maple
生活中许多目标的高度和水平距离需要进行测量。目前主要的测量方法，仍以传统的皮尺丈量为主，测量效率不高，有时还很不方便，没有技术成熟的数字式测高测距产品。以基本的数学方法为理论依据，利用遥控小车做为载体，采用角度传感器测量角度、霍尔传感器测量水平距离等，通过单片机LM3S615进行数据计算，实现了对待测目标物体的高度、水平距离等数据的快速、精确和数字式的测量，高度测量精度可达99.06%，水平测量精度则可达98.06%。 Abstract: In our lives， the height and hOrizontal distance of some goals are needed to be measured. Because the currently used methods are still traditional tape-based measuring methods， and the measuring efficiency is low and inconvenient so some kinds of digital and pOrtable measuring methods Or instruments are needed. Based on the basic math theOry， this paper designed and manufactured a pOrtable， digital and remote controlled measuring mobile small vehicle， which assembled with angle measuring sensOr fOr angle measurement and Hall sensOr fOr hOrizontal distance measuring. MCU LM3S615 calculated the height and hOrizontal distance data gotten from these sensOrs. The measuring process is simple， the measuring results are mOre accurate and the measuring efficiency is higher than traditional measure instruments. The accuracy of height and distance measurement can reach 99.06% and 98.06%.
上传时间： 2013-10-30
上传用户：jackandlee
提出一种基于凌阳单片机的步进电机加减速的控制方法。采用凌阳科技推出的16位结构工控单片机SPMC75F2413A为控制器，由Allegro公司生产的两相步进电机专用驱动器件SLA7042M构成步进电机的驱动电路，在传统的3段直线加减速控制算法基础上增加至7段S形曲线加减速过程，控制步进电机的启动和停止。实验结果表明，该控制方法克服了直线加减速中不连续、易造成系统冲击的问题，整个系统实现柔性控制，电机启动、停止连续性能提高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%
上传时间： 2013-12-08
上传用户：jiangfire
针对目前汽车追尾事件频发问题，提出一种防汽车车前和车后追尾的安全装置设计。该设计以高性能、低功耗的8位AVR微处理器ATmega8L为核心，结合霍尔式车速传感器、激光雷达测距装置和MMA7260QT加速度传感器，能够兼顾车前和车后，摒弃以往设计中只考虑车前或车后单一性缺点，尤其适用于高速、夜晚或新手行车。 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.
上传时间： 2013-10-14
上传用户：GavinNeko
实时时钟是微机保护装置的重要部件，在讨论PCF8583结构与功能的基础上，提出采用dsPIC33F系列微处理器与串行I2C时钟PCF8583的接口设计方案，给出了相应的接口电路与软件流程。该设计方案结构简单，可靠性高，开发周期短，具有一定的实用与参考价值。所设计的微机保护装置已投入现场运行，效果良好。 Abstract: Real-time clock chip is an impOrtant part in microcomputer protection device.Based on discussing the structure and function of PCF8583，a new interface scheme which uses dsPIC33F microprocessOr and serial clock chip（I2C）PCF8583is proposed.The method of the circuit design and the main software flow are introduced in this paper.The scheme has simple structure，higher reliability and shOrter exploitation cycle，so has definite practicality Or reference value.The microcomputer protection device has been put into operation with better effects.
上传时间： 2013-11-18
上传用户：Thuan
阐述了一个由上位PC机和AT89C52下位单片机组成的主从分布式温度巡回检测系统。主从机采用RS-485 串行通讯标准进行通信，可在下位单片机实现基本的温度数据巡回检测基础上，由上位PC机实现综合处理功能或扩展为远程操作。整个系统具有巡检速度快，扩展性好的特点。 Abstract: In this paper,a top PC and AT89C52 under-bit microcontrollers from the main component of the tour distributed temperature detection system is presented. Master and slave can use RS-485 serial communication standards fOr communications.Based on next-bit machine fOr basic goods temperature detected data Tour, the top can achieve the integrated treatment of PC functions Or fOr the expansion of long-distance operation. The entire inspection system is fast, expansion.
上传时间： 2013-10-13
上传用户：zhoujunzhen
在汽车发动机起动时，若发动机起动后起动机不能及时断电，将会烧毁起动机或损坏飞轮齿环；若变速器不在空档位置起动，则起动机的瞬间动力将使汽车位移，还可能引起交通事故和人身安全。为此介绍一种利用NXP P89LPC901单片机控制的汽车起动保护控制器，通过检测汽车起动开关、变速箱档位、发动机转速，实现对汽车发动机起动过程检测和保护。起动保护控制器在发动机起动过程中通过采用逐个关闭打开负载系统，解决汽车发动机过程中因起动电流大而对汽车电源的冲击影响,延长了电瓶寿命。 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.
上传时间： 2013-10-15
上传用户：mikesering
基于CC1110单片机公交报站系统主要由CC1110单片机最小系统和WT588D语音模块组成，提出了如何实现语音报站，通过无线通信SimpliciTI网络协议实现公交站台的自动播报和OLCD液晶显示公交运行的各类信息。结果表明，该公交报站系统报站准确率99%，价格比同类产品下降了300%以上，系统组成结构简单，提高了系统的抗干扰性和稳定性，也便于携带。 Abstract: The bus stop announcement system based on CC1110 MCU is composed of CC1110 MCU minimum system and WT588D voice module. How to achieve the voice announcing is put fOrward.The bus-stop will announce automatically and display on the OLCD by means of wireless communication SimpliciTI netwOrk protocol. As a result， the bus station stop announcement systems repOrted 99% accuracy rate， price of similar products declined by 300% Or mOre， system of simple structure， improve the anti-jamming and stability of the power system， it is also pOrtable.
上传时间： 2013-10-21
上传用户：baby25825
以AVR单片机ATmega8和USB接口器件PDIUSBD12为核心，基于标准的USB1.1协议，设计一种通用USB接口模块，以满足嵌入式系统中对USB接口的需求。对模块的硬件电路或单片机固件程序的硬件接口层稍加修改即可用于其他各种微处理器。该模块可为各种嵌入式系统增加USB接口,实现与USB主机系统通信。 Abstract: Based on AVR microcontroller ATmega8 and USB interface chip PDIUSBD12, a general USB interface module is designed accOrding to USB1.1 protocol fOr various requirements of embedded systems. Only with few modifications in circuit Or hardware abstract layer of firmware, the module can be used on many types of microprocessOrs. All kinds of embedded systems can realize high speed and stable communication with USB host systems, owing to the facility of this module.
上传时间： 2014-01-08
上传用户：赵云兴
