Digitemp Junior – An RS-232 Port-Powered Digital Thermometer 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 rel- atively easy to write custom sOFtware for receiving, recording, and analyzing ambient temperature data. Best of all, Digitemp Jr. requires no external power sup- plies or batteries. It is powered directly by the RS-232 port.
上传时间： 2013-10-21
上传用户：baitouyu
c语言既具有一般高级语言的特点，又能直接对计算机的硬件进行操作．Keil C51是德国Keil sOFtware公司出品的51系列兼容单片机c语言软件开发系统．与汇编相比，c语言在功能、结构性、可读性、可维护性上有明显的优势，因而易学易用．Keil C51继承了c语言对数据有很强的表达能力的优点，具有丰富的运算符，在算术运算和逻辑运算上更体现了汇编不可比拟的优点．由于C51语言具有强大的数据处理能力和数学运算库函数，当涉及到复杂的数学运算，使用C51语言往往会比较方便．在一般情况下，由C51编译生成的代码不论长度还是程序运行速度均能适应程序要求．利用C51开发单片机系统，不但可以使编程工作量大为减少，而且使软件维护、修改亦变得非常方便．
上传时间： 2014-01-25
上传用户：yyxy
针对目前使用的RS232接口数字化B超键盘存在PC主机启动时不能设置BIOS，提出一种PS2键盘的设计方法。基于W78E052D单片机，采用8通道串行A/D转换器设计了8个TGC电位器信息采集电路，电位器位置信息以键盘扫描码序列形式发送，正交编码器信号通过XC9536XL转换为单片机可接收的中断信号，软件接收到中断信息后等效处理成按键。结果表明，在满足开机可设置BIOS同时，又可实现超声特有功能，不需要专门设计驱动程序，接口简单，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.
上传时间： 2013-10-10
上传用户：asdfasdfd
在航电系统维护过程中，为解决定位故障的效率和降低维修成本等问题，提出了基于ICD（Interface Control Document，接口控制文件）的1553B总线的信息监控系统模型。该系统运用数据采集卡对总线中传输的信号有无失真、偏差等电气特性进行检测，并使用1553B通讯卡通过测控软件LabWindows/CVI编程与ICD数据库的动态链接，实现总线信息的解析和故障的判断。与传统的维护过程相比，这种模型能够从信号的电气特性以及信息的解析等全方位的去检测判断故障的来源，并且能够广泛在其他1553B总线系统内扩展应用。验证表明该监控系统可以对总线信息进行快速有效地监测分析，能满足应用需求。 Abstract: In the process of avionics system maintenance， to solve the problems such as improving the efficiency of fast orientation to troubles and reducing maintenance cost， system of 1553B bus information monitor model based on ICD was proposed. The system observed whether the data which transmitted on the bus appear distortion and deviation by using data acquisition card. And using 1553B communication card programming of the measure sOFtware LabWindows/CVI and the dynamic linking of ICD database， message analysis and fault estimation could be realized. Compared with traditional maintenance， this model can all-dimensionally detect and analyze the source of faults from both electrical characteristics of the signal and message analysis， and it can be widely applied in the other 1553B system. Experiment shown that this monitor system can effectively detect and analyze the bus message and can meet the application requirements.
上传时间： 2013-11-23
上传用户：18752787361
为了有效地提升铅酸蓄电池的使用寿命，同时实现对充电过程的监控，设计出一种用单片机控制的36 V铅酸蓄电池充电电源。本电路采用反激式拓扑，连续电流工作模式，电源管理IC设计在电源的副边，由ELAN公司的EM78P258N单片机模拟，是用可编程器件模拟电源管理IC，实现智能电源低成本化的一次成功尝试，通过对单片机的软件设计实现了充电电源的状态显示、充电时间控制、报警、过温保护、过压保护、过流保护等功能。本充电器真正的实现了铅酸蓄电池的三段式充电过程，其最高输出功率可达90 W，效率约85%，成本不到20元，具有很高的市场竞争力。 Abstract: In order to extend the life of lead-acid battery efficiently and supervise the charging process meanwhile， a 36V lead-acid battery charge powe supply controlled by microcontroller is designed. The charger is flyback switching power supply and works in CCM mode. A EM78P258N microcontroller made by ELAN microelectronics corporation is used as power management IC which is designed at the secondary circuit. The project is a successful attempt to low-cost intelligent power used microcontroller simulating power management IC. The charger also has the functions of the status reveal， charge time control， alarming， thermal protect， current limit and overvoltage protect by the sOFtware design. The circuit actually implements the three-step charge process， whose power is up to 90W and whose efficiency can get 85%. The net cost of this charger is less than 20 RMB， so that the charger is of powerful market competitiveness.
上传时间： 2013-11-16
上传用户：cepsypeng
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
以C8051F020为核心处理器，设计无线传感器网络数据采集系统。系统采用SZ05-ADV型无线通讯模块组建Zigbee无线网络，结合嵌入式系统的软硬件技术，完成终端节点的8路传感器信号的数据采集。现场8路信号通过前端处理后，分别送入C8051F020的12位A/D转换器进行转换。经过精确处理、存储后的现场数据，通过Zigbee无线网络传送到上位机，系统可达到汽车试验中无线测试的目的。 Abstract: This paper designs a wireless sensor network system for data acquisition with C8051F020 as core processors.The system used SZ05-ADV wireless communication module，set up a Zigbee wireless network， combined with hardware and sOFtware technologies of embedded systems，completed the end-node 8-locale sensor signal data acquisition.Eight locale signals were sent separately into the 12-bit ADC of C8051F020 for conversion through front treatment.After accurate processing and storage，the locale data was transmitted to the host computer through Zigbee wireless.The system achieves the purpose of wireless testing in vehicle trial.
标签： C8051F020 Zigbee 汽车测试 系统设计
上传时间： 2013-11-23
上传用户：dsgkjgkjg
以太网和CAN总线应用广泛，但由于其通信协议不同，两种总线器件间无法进行数据通信，因此，设计了基于CP2200与C8051F040的以太网总线与CAN总线接口转换电路，并给出部分相关硬件电路与软件设计分析。在保证数据完整和协议可靠的前提下，通过握手协议和简化的以太网协议，不仅实现了以太网数据与CAN数据的转发，同时还顺利的解决了以太网的高速性与CAN的低速率冲突，以及两者数据包之间的大小不同的矛盾。 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.
上传时间： 2013-10-15
上传用户：Ants
单片机作为一种微型计算机，其内部具有一定的存储单元（8031除外），但由于其内部存储单元及端口有限，很多情况下难以满足实际需求。为此介绍一种新的扩展方法，将数据线与地址线合并使用，通过软件控制的方法实现数据线与地址线功能的分时转换，数据线不仅用于传送数据信号，还可作为地址线、控制线，用于传送地址信号和控制信号，从而实现单片机与存储器件的有效连接。以单片机片外256KB数据存储空间的扩展为例，通过该扩展方法，仅用10个I/O端口便可实现，与传统的扩展方法相比，可节约8个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.
上传时间： 2014-12-26
上传用户：adada
