针对目前采用的热敏电阻测量方法，提出了采用单总线数字式温度传感器DS18B20和单片机组成的新型温度测量仪。介绍DS18B20的结构和工作原理，以及单总线工作原理，给出了由Mega8单片机和DS18B20构成的单总线温度测量仪的硬件电路及软件流程图。经试验基于单总线器件DS18B20的温度测量仪，具有测量准确、测温范围宽、体积小、控制方便等优点。 Abstract: This paper brings forward a new temperature meter composed of 1-Wire temperature sensor DS18B20 and MCU which has advantage of the thermistor. In the article, the DS18B20＇s structure and controlling principles are introduced and hardware circuit and software diagram of the temperature meter are given.After been tested,the temperature meter has the advantages of accurate measurement, wide temperature range, small volume and convenient controlling.
上传时间： 2013-10-31
上传用户：hzy5825468
介绍一种以MSP430单片机为基础的智能频率测量系统，采用硬件逻辑与软件指令相结合的方式控制闸门，实现0 MHz~10 MHz范围内无档切换的等精度测量。 Abstract: An intelligent frequency measurement system based on MSP430 singlechip is introduced. The system uses a way that can combine hardware logic and software instructions to contronl the strobe ,and completes the functions of equal precision in the range of 0MHz~10MHz without shifting
上传时间： 2013-10-28
上传用户：dbs012280
介绍一种基于单片机的多路温度采集及监控系统，能够测量6路温度信号，具有计算机联网功能，各测量点可以单独监控和设置，可根据用户的需求自动控制。测量温度范围为-10 ℃～200 ℃，控制方式采用模拟量调压模式。该系统具有控制精度高、冲击小等特点。 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.
上传时间： 2013-10-23
上传用户：bjgaofei
为解决输油管道温度压力参数实时监测的问题，设计了以C8051F930单片机作为控制核心的超低功耗输油管道温度压力远程监测系统。现场仪表使用高精度电桥采集数据，通过433 MHz短距离无线通信网络与远程终端RTU进行通信，RTU通过GPRS网络与PC上位机进行远程数据传输，在上位机中实现数据存储和图形化界面显示，从而实现输油管道温度压力参数的实时监测和异常报警。经实验证明，该系统的12位数据采集精度满足设计要求，漏码率小于1%，正常工作时间超过5个月，能实时有效地监测输油管道的温度压力参数，节省大量人工成本，有效预防管道参数异常造成的经济损失和环境污染。 Abstract: In order to solve the problems on real-time monitoring of pipeline temperature and pressure parameters， the ultra-low power remote pipeline temperature and pressure monitoring system was designed by using the single chip processor C8051F930 as the control core. The high-precision electric bridge was used in field instruments for data collection， the 433MHz short-range wireless communication network was used to make communication between field instrument and RTU， the GPRS was used by the RTU to transmit data to the PC host computer， and the data was stored and displayed in the PC host computer， so the real-time monitoring and exception alerts of pipeline temperature and pressure parameters were achieved. The experiment proves that the system of which error rate is less than 1% over five months working with the 12-bit data acquisition accuracy can effectively monitor the pipeline temperature and pressure parameters in real time， it saves a lot of labor costs and effectively prevents environmental pollution and economic losses caused by abnormal channel parameters.
上传时间： 2013-11-07
上传用户：cuibaigao
1 FEATURES· Single chip LCD controller/driver· 1 or 2-line display of up to 24 characters per line, or2 or 4 lines of up to 12 characters per line· 5 ′ 7 character format plus cursor; 5 ′ 8 for kana(Japanese syllabary) and user defined symbols· On-chip:– generation of LCD supply voltage (external supplyalso possible)– generation of intermediate LCD bias voltages– oscillator requires no external components (externalclock also possible)· Display data RAM: 80 characters· Character generator ROM: 240 characters· Character generator RAM: 16 characters· 4 or 8-bit parallel bus or 2-wire I2C-bus interface· CMOS/TTL compatible· 32 row, 60 column outputs· MUX rates 1 : 32 and 1 : 16· Uses common 11 code instruction set· Logic supply voltage range, VDD - VSS: 2.5 to 6 V· Display supply voltage range, VDD - VLCD: 3.5 to 9 V· Low power consumption· I2C-bus address: 011101 SA0.
上传时间： 2013-11-08
上传用户：laozhanshi111
The SN65LBC170 and SN75LBC170 aremonolithic integrated circuits designed forbidirectional data communication on multipointbus-transmission lines. Potential applicationsinclude serial or parallel data transmission, cabledperipheral buses with twin axial, ribbon, ortwisted-pair cabling. These devices are suitablefor FAST-20 SCSI and can transmit or receivedata pulses as short as 25 ns, with skew lessthan 3 ns.These devices combine three 3-state differentialline drivers and three differential input linereceivers, all of which operate from a single 5-Vpower supply.The driver differential outputs and the receiverdifferential inputs are connected internally to formthree differential input/output (I/O) bus ports thatare designed to offer minimum loading to the buswhenever the driver is disabled or VCC = 0. Theseports feature a wide common-mode voltage rangemaking the device suitable for party-lineapplications over long cable runs.
上传时间： 2013-10-13
上传用户：ytulpx
FeaturesThe following standard features are provided.• Choice of RTOS scheduling policy1. Pre-emptive:Always runs the highest available task. Tasks of identical priorityshare CPU time (fully pre-emptive with round robin time slicing).2. Cooperative:Context switches only occur if a task blocks, or explicitly callstaskYIELD().• Co-routines (light weight tasks that utilise very little RAM).• Message queues• Semaphores [via macros]• Trace visualisation ability (requires more RAM)• Majority of source code common to all supported development tools• Wide range of ports and examples
上传时间： 2013-10-13
上传用户：13162218709
The Controller Area Network (CAN) is a serial, asynchronous, multi-master communication protocol forconnecting electronic control modules, sensors and actuators in automotive and industrial applications.With the SJA1000, Philips Semiconductors provides a stand-alone CAN controller which is more than a simpleeplacement of the PCA82C200.Attractive features are implemented for a wide range of applications, supporting system optimization, diagnosisand maintenance.
标签： Stand-alone contro 1000 SJA
上传时间： 2013-11-18
上传用户：yxgi5
The P82B715 I2C Buffer was designed toextend the range of the local I2C bus out to50 Meters. This application note describesthe results of testing the buffer on severaldifferent types of cables to determine themaximum operating distances possible. Theresults are summarized in a table for easyreference.
标签： extender P82B715 Using I2C
上传时间： 2014-12-28
上传用户：lou45566
状态机设计:8.1.1 数据类型定义语句TYPE语句的用法如下：TYPE 数据类型名IS 数据类型定义OF 基本数据类型;或TYPE 数据类型名IS 数据类型定义;TYPE st1 IS ARRAY ( 0 TO 15 ) OF STD_LOGIC ;TYPE week IS (sun，mon，tue，wed，thu，fri，sat) ; 8.1.1 数据类型定义语句TYPE m_state IS ( st0，st1，st2，st3，st4，st5 ) ;SIGNAL present_state，next_state : m_state ;TYPE BOOLEAN IS (FALSE，TRUE) ；TYPE my_logic IS ( '1' ，'Z' ，'U' ，'0' ) ;SIGNAL s1 : my_logic ;s1 <= 'Z' ;SUBTYPE 子类型名IS 基本数据类型RANGE 约束范围;SUBTYPE digits IS INTEGER RANGE 0 to 9 ;
标签： 状态
上传时间： 2013-11-05
上传用户：nem567397
