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Zero-order-hold

  • 基于MSP430F149的无线环境监测传感器系统设计

    为了提高环境参数采集的自动化水平,提升效率,设计了无线传感器系统。本系统运用了传感器技术、通信技术和单片机技术,实现了对环境温度、湿度、光照度以及可燃性气体浓度等参数的检测。它能够实时地与上位机进行无线通信,满足对环境参数实时监测的要求。 Abstract:  In order to increase the degree of automation and improve the efficiency of the environment monitoring parameters,the wireless sensor system was developed.Combining with the technique of sensor,automatic monitoring,communication and single-chip microcomputer,it realized real-time monitoring environment parameters,such as temperature,humidity,illumination,concentration of com- bustible gas and so on.At the same time it can communicate with upper personal computers,satisfy the desire of real-time monitoring.

    标签: 430F F149 MSP 430

    上传时间: 2013-11-22

    上传用户:longlong12345678

  • 基于C8051F930的管道温度压力远程监测系统

       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.

    标签: C8051F930 温度 压力 远程监测系统

    上传时间: 2013-11-07

    上传用户:cuibaigao

  • MAX7456在可视倒车雷达中的应用

    为解决传统可视倒车雷达视频字符叠加器结构复杂,可靠性差,成本高昂等问题,在可视倒车雷达设计中采用视频字符发生器芯片MAX7456。该芯片集成了所有用于产生用户定义OSD,并将其插入视频信号中所需的全部功能,仅需少量的外围阻容元件即可正常工作。给出了以MAX7456为核心的可视倒车雷达的软、硬件实现方案及设计实例。该方案具有电路结构简单、价格低廉、符合人体视觉习惯的特点。经实际装车测试,按该方案设计的可视倒车雷达视场清晰、提示字符醒目、工作可靠,可有效降低驾驶员倒车时的工作强度、减少倒车事故的发生。 Abstract:  A new video and text generation chip,MAX7456,was used in the design of video parking sensor in order to simplify system structure,improve reliability and reduce cost. This chip included all the necessary functions to generate user-defined OSDs and to add them into the video signals. It could be put into work with addition of just a small number of resistances and capacitors. This paper provided software and hardware implementation solutions and design example based on the chip. The system had the characteristics of simplicity in circuit structure,lower cost,and comfort for the nature of human vision. Loading road test demonstrates high video and text display quality and reliable performance,which makes the driver easy to see backward and reduces chance of accidents.

    标签: 7456 MAX 可视倒车 中的应用

    上传时间: 2013-12-10

    上传用户:qiaoyue

  • 基于IC卡的新型供暖计费系统设计

    将现行的供暖计费方式由按建筑面积计费变为按消耗的热能计费是供暖计费方式发展趋势,为了满足这一计费方式变化的需要,设计了基于IC卡的预付费式新型供暖计费系统,通过测量用户采暖系统进出口的温度和流量,计算用户消耗的热能,利用IC卡记录用户预付费的金额和当年热能的单价,根据热能消耗和当年热能的单价计算用户采暖费,根据实际发生的供暖费用和预付费金额控制供暖的开停,这一计费方式的变化使供暖计费更趋合理。 Abstract:  It is trend that the mode of heat charging is changed from billing by building area to by thermal energy. In order to meet the needs of heat charging mode changing, a new system of heat charging based on IC card is proposed. The user?蒺s energy consumption is calculated by measuring the user inlet and outlet temperature and flow,using the IC card to record the prepaid amount and the current price of heat. The user?蒺s heating costs is calculated according to energy consumption and current price, according to actual heating costs and prepaid amount,the system controls the heating opening or stopping. It is more reasonable that calculated heating costs by user heat consumption

    标签: IC卡 计费 系统设计

    上传时间: 2013-10-14

    上传用户:大融融rr

  • 基于MSP430单片机和DS18B20的数字温度计

    为了在工业生产及过程控制中准确测量温度,设计了一种基于低功耗MSP430单片机的数字温度计。整个系统通过单片机MSP430F1121A控制DS18B20读取温度,采用数码管显示,温度传感器DS18B20与单片机之间通过串口进行数据传输。MSP430系列单片机具有超低功耗,且外围的整合性高,DS18B20只需一个端口即可实现数据通信,连接方便。通过多次实验证明,该系统的测试结果与实际环境温度一致,除了具有接口电路简单、测量精度高、误差小、可靠性高等特点外,其低成本、低功耗的特点使其拥有更广阔的应用前景。 Abstract:  In order to obtain accurate measuring temperature in industrial production and process control, a digital thermometer based on MSP430 MCU is designed. The system uses MSP430F1121A MCU to control DS18B20, and gets the temperature data, which is displayed on the LED. The temperature sensor DS18B20 and MCU transmit data through serial communication. MSP430 series has ultra-low power and high integration, DS18B20 only needs one port to achieve data communication. Through many experimental results prove, this system is consistent with actual environment temperature. The system has characteristics of interface circuit simple, high measuring accuracy, minor error, high reliability, besides, the characteristics of low cost and low power make it having vaster application prospect.

    标签: MSP 430 18B B20

    上传时间: 2013-10-16

    上传用户:wettetw

  • SUNPLUSIT编程工具Q-Writer使用说明书

    Important Notice SUNPLUS INNOVATION TECHNOLOGY INC. reserves the right to change this documentation without prior notice.  Information provided by SUNPLUS INNOVATION TECHNOLOGY INC.  is believed to be accurate and reliable.  However, SUNPLUS INNOVATION TECHNOLOGY INC.makes no warranty for any errors which may appear in this document.  Contact SUNPLUS INNOVATION TECHNOLOGY INC.to obtain the latest version of device specifications before placing your order.  No responsibility is assumed by SUNPLUS INNOVATION TECHNOLOGY INC. for any infringement of patent or other rights of third parties which may result from its use. In addition, SUNPLUSIT products are not authorized for use as critical components  in life support systems or aviation systems, where a malfunction or failure of the product may reasonably be expected to result in significant injury to the user, without the express written approval of SunplusIT

    标签: SUNPLUSIT Q-Writer 编程工具 使用说明书

    上传时间: 2013-10-13

    上传用户:brain kung

  • CAT25128-128Kb的SPI串行CMOS EEPRO

    The CAT25128 is a 128−Kb Serial CMOS EEPROM device internally organized as 16Kx8 bits. This features a 64−byte page write buffer and supports the Serial Peripheral Interface (SPI) protocol. The device is enabled through a Chip Select (CS) input. In addition, the required bus signals are clock input (SCK), data input (SI) and data output (SO) lines. The HOLD input may be used to pause any serial communication with the CAT25128 device. The device featuressoftware and hardware write protection, including partial as well as full array protection.

    标签: 25128 EEPRO CMOS CAT

    上传时间: 2013-11-15

    上传用户:fklinran

  • AT89C2051驱动步进电机的电路和源码

    AT89C2051驱动步进电机的电路和源码:AT89C2051驱动步进电机的电路和源码 程序:stepper.c stepper.hex/* * STEPPER.C * sweeping stepper's rotor cw and cww 400 steps * Copyright (c) 1999 by W.Sirichote */#i nclude c:\mc5151io.h /* include i/o header file */ #i nclude c:\mc5151reg.hregister unsigned char j,flag1,temp; register unsigned int cw_n,ccw_n;unsigned char step[8]={0x80,0xc0,0x40,0x60,0x20,0x30,0x10,0x90} #define n 400/* flag1 mask byte 0x01 run cw() 0x02 run ccw() */main(){ flag1=0; serinit(9600); disable(); /* no need timer interrupt */ cw_n = n; /* initial step number for cw */ flag1 |=0x01; /* initial enable cw() */while(1){ { tick_wait(); /* wait for 10ms elapsed */energize(); /* round-robin execution the following tasks every 10ms */ cw(); ccw(); } }}cw(){ if((flag1&0x01)!=0) { cw_n--; /* decrement cw step number */ if (cw_n !=0) j++; /* if not zero increment index j */ else {flag1&=~0x01; /* disable cw() execution */ ccw_n = n; /* reload step number to ccw counter */ flag1 |=0x02; /* enable cww() execution */ } }

    标签: C2051 2051 89C AT

    上传时间: 2013-11-21

    上传用户:boyaboy

  • TMS320C6000 Assembly Language

    Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their productsor to discontinue any product or service without notice, and advise customers to obtain the latestversion of relevant information to verify, before placing orders, that information being relied onis current and complete. All products are sold subject to the terms and conditions of sale suppliedat the time of order acknowledgement, including those pertaining to warranty, patentinfringement, and limitation of liability.

    标签: Assembly Language C6000 320C

    上传时间: 2013-11-12

    上传用户:chens000

  • Input Signal Rise and Fall Tim

    All inputs of the C16x family have Schmitt-Trigger input characteristics. These Schmitt-Triggers are intended to always provide proper internal low and high levels, even if anundefined voltage level (between TTL-VIL and TTL-VIH) is externally applied to the pin.The hysteresis of these inputs, however, is very small, and can not be properly used in anapplication to suppress signal noise, and to shape slow rising/falling input transitions.Thus, it must be taken care that rising/falling input signals pass the undefined area of theTTL-specification between VIL and VIH with a sufficient rise/fall time, as generally usualand specified for TTL components (e.g. 74LS series: gates 1V/us, clock inputs 20V/us).The effect of the implemented Schmitt-Trigger is that even if the input signal remains inthe undefined area, well defined low/high levels are generated internally. Note that allinput signals are evaluated at specific sample points (depending on the input and theperipheral function connected to it), at that signal transitions are detected if twoconsecutive samples show different levels. Thus, only the current level of an input signalat these sample points is relevant, that means, the necessary rise/fall times of the inputsignal is only dependant on the sample rate, that is the distance in time between twoconsecutive evaluation time points. If an input signal, for instance, is sampled throughsoftware every 10us, it is irrelevant, which input level would be seen between thesamples. Thus, it would be allowable for the signal to take 10us to pass through theundefined area. Due to the sample rate of 10us, it is assured that only one sample canoccur while the signal is within the undefined area, and no incorrect transition will bedetected. For inputs which are connected to a peripheral function, e.g. capture inputs, thesample rate is determined by the clock cycle of the peripheral unit. In the case of theCAPCOM unit this means a sample rate of 400ns @ 20MHz CPU clock. This requiresinput signals to pass through the undefined area within these 400ns in order to avoidmultiple capture events.For input signals, which do not provide the required rise/fall times, external circuitry mustbe used to shape the signal transitions.In the attached diagram, the effect of the sample rate is shown. The numbers 1 to 5 in thediagram represent possible sample points. Waveform a) shows the result if the inputsignal transition time through the undefined TTL-level area is less than the time distancebetween the sample points (sampling at 1, 2, 3, and 4). Waveform b) can be the result ifthe sampling is performed more than once within the undefined area (sampling at 1, 2, 5,3, and 4).Sample points:1. Evaluation of the signal clearly results in a low level2. Either a low or a high level can be sampled here. If low is sampled, no transition willbe detected. If the sample results in a high level, a transition is detected, and anappropriate action (e.g. capture) might take place.3. Evaluation here clearly results in a high level. If the previous sample 2) had alreadydetected a high, there is no change. If the previous sample 2) showed a low, atransition from low to high is detected now.

    标签: Signal Input Fall Rise

    上传时间: 2013-10-23

    上传用户:copu