提出了用“过采样”技术使在有用的测量频带内的信噪比得到改善, 从而提高ADC 测量的分辨率。并利用Matlab 对其结论进行仿真, 且在TMS320L F2407 DSP 上予以实现,结果表明信噪比和测量分辨率明显提高。
上传时间： 2013-11-20
上传用户：fairy0212
TTL电平和CMOS电平总结
上传时间： 2013-10-09
上传用户：Zxcvbnm
18B20温度测量
上传时间： 2013-10-19
上传用户：guanhuihong
为解决电致变色器件的颜色变化受外界环境颜色控制的问题，设计了一种基于单片机的便携式颜色自适应识别电路。与传统颜色识别电路相比较，该电路利用数字式的颜色传感器来获取外界环境颜色，产生的数字颜色信号易于单片机进行处理。在电路中，下位机部分主要负责获取电致变色器件变色参数及控制电致变色器件的颜色变化;而上位机部分主要负责把下位机获取的电致变色器件变色参数进行电压到颜色的曲线拟合，并通过蓝牙通信把拟合曲线参数传递给下位机。结果表明，该电路能自动根据环境颜色提供-4~4 V范围步进为0.1 V的电压来驱动电致变色器件的颜色显示，与传统的颜色识别电路设计相比，识别的精度和速度都得到了明显改善。 Abstract: In this paper， a portable adaptive circuit for color identification(PACCI) based on MCU was designed. Compared to the traditional color identification circuit， the PACCI adopts digital sensor to detect the color data from external environment and further generate digital color data， which can be processed easily by MCU. In PACCI， the slave is mainly responsible for detecting the color parameters of the corresponding elcreochromic device and further driving it. For the master， which is mainly responsible for the color curve fitting based on the parameters of the electrochromic device， and transmits the fitting parameters to the slave through the bluetooth device. The results show that the PACCI can provide the basis voltage range from -4V to 4V automatically based on the colors of external environment with step as 0.1V to drive the corresponding electrochromic device. Compared to the traditional color recognition circuit， the recognition accuracy and speed of PACCI have been improved significantly.
上传时间： 2013-11-09
上传用户：franktu
设计了一种基于PIC16C71单片机的数字水温配制阀。该配制阀采用NTC热敏电阻作温度传感器，与固定电阻组成简单分压电路作为水温测量电路，利用PIC16C71单片机内置的8位A/D转换器把热敏电阻上的模拟电压转换为数字量，PIC16C71单片机控制直流电机驱动混水阀调节冷热水的混合比例实现水温调节。给出了控制电路图，对水温测量电路的参数选择和测温精度作了详细讨论。实验和分析表明，选用阻值较大的NTC热敏电阻和分压电阻可较好地解决热敏电阻因功耗较大造成的热击穿问题。 Abstract: A digital valve for controlling water temperature based on PIC16C71 was presented in this paper.A bleeder circuit which consisted of a NTC thermistor as temperature sensor and a fixed resistance was designed as water temperature measuring circuit.The analog voltage on the thermistor was converted into digital signal by a 8-bit A/D converter embedded in PIC16C71. Based on the digital signal， the MCU PIC16C71 drived the valve by a DC motor to adjust the water temperature through adjusting the proportion of hot water and cold water.The circuit diagram of controller was given，the principle，the component parameters and the accuracy of measuring temperatures were also dissertated in detail. It was found by experiment and analysis that thermal breakdown of thermistor caused by high power could be solved by selecting thermistor and fixed resistance with high impedance value.
上传时间： 2013-11-08
上传用户：Yue Zhong
为提高电容测量精度，针对电容式传感器的工作原理设计了基于PIC16LF874单片机电容测量模块。简单阐述了电容测量电路的应用背景和国内外研究现状，介绍了美国Microchip公司PIC16LF874单片机的特性。电容式传感器输出的动态微弱电容信号通过PS021型电容数字转换器把模拟量数据转换成数字量数据，所测数据由PIC16LF874单片机应用程序进行处理、显示和保存。实验结果表明，固定电容标称值为10~20 pF 的测量值相对误差在1%以内，同时也可知被测电容容值越大，测量值和标称值相对误差越小。 Abstract: To improve the accuracy of capacitance measurement，aimed at the principle of work of mercury capacitance acceleration transducer，the design of micro capacitance measurement circuit is based on the key PIC16LF874 chip. Briefly discusses the application of the capacitance measuring circuit for the background and status of foreign researchers，focusing on the United States PIC16LF874 microcontroller features. Capacitive sensor outputed signal through the dynamics of weak PS021-chip capacitors （capacitancedigital converter） to convert analog data into digital data，the measured data from the PIC16LF874 microcontroller application process， display and preservation. Experimental results show that the fixed capacitor 10pF ~ 20pF nominal value of the measured value of relative error is within 1%，but also it canbe seen the value of the measured capacitance larger，measuring value and the nominal value of relative error smaller.
上传时间： 2013-10-29
上传用户：wojiaohs
设计一种基于P89V51RD2的功率因数测量仪，采用光电隔离器和专用数码管驱动器。该测量仪是以增强型单片机P89V51RD2为核心，大大简化系统硬件设计。而软件部分采用模块化设计思想，采用中值滤波和小数补偿算法，实现功率因数的高精度测量。实验测试表明，该功率因数测量仪测量精度高，运行稳定可靠。 Abstract: A power－factor measurement instrument based on P89V51RD2is designed，which uses optical coupler and specific LED drive chip.The power factor measurement instrument uses P89V51RD2as a core of which greatly simplifies the system design.Furthermore，modularization software is developed in detail.The high precision power－factor measuring system is realized by the center value filter and fractional compensation algorithm.Experiments manifests that the power－ factor measurement instrument is high precision，steady and reliable.
上传时间： 2014-12-27
上传用户：CHINA526
介绍了一种基于C8051F020单片机的多路压力测量仪。该测量仪选用电阻应变式压力传感器采集压力信号，并经放大电路处理后送入C8051F020单片机，再由C8051F020单片机内部的A/D转换器将采集到的压力信号进行模数转化，然后分别对数据进行存储和显示。该测量仪能测量6路压力信号，并且各测量点都能单独检测和设置。由于采用了C8051F020单片机，简化了硬件电路，增强了抗干扰能力，使得测量仪具有测量精度高，冲击小等特点。 Abstract: A measurement apparatus for multi-channel pressure based on single chip microcomputer is introduced.It can measure 6 channels signal of the pressure，and the pressure measure points can be detection and located individually.The pressure signal sampling is obtained by resistor stress-type pressure sensors，the digital signals of 6 channels are collected through amplifying and adjustment circuit of pressure signals and internal integrated A/D converter of MCU.Finally，and it realizes the function to store and display data separately.C8051F020 was used to made hardware circuit simple，and it also enhanced the anti-interference ability.It features high precision and little impact.
上传时间： 2013-11-16
上传用户：yare
气压是气象监测中的一个重要参数，提出了一种气压数据采集模块设计方案，该模块采用数字气压传感器MS5534B、MSP430单片机MSP430F2272和带实时时钟（RTC）64 KB铁电存储器。通过低功耗软件设计方法以微安级整体平均功耗实现了气压数据的采集和存储，适合电池供电的连续高精度气压采集应用。给出了模块的软硬件设计以及MS5534B的性能指标和使用经验。 Abstract: Air pressure is an important parameter in weather monitor.This paper futs forward a new design scheme of low power-air pressure data acquisition module.The module uses a digital output barometer sensor MS5534B,MSP430 microcontroller MSP430F2272 and integrated RTC 64KB FRAM,precision air pressure measurement and storage chip.Another point of this module is low power consumption, so it is well suited for battery powered air pressure data acquisition applications. At the same time,the software and hardware deign of module is presented,And the speciaties and use notices of MS5534B are given.
上传时间： 2014-12-27
上传用户：drink！
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
