便攜式信號采集在機(jī)器健康診斷系統(tǒng)中有較高的應(yīng)用價值。機(jī)器健康診斷的信號特點是包括低頻信號。本文研究是為了實現(xiàn)簡易而且低成本的低頻便攜式信號采集。以MicroChip公司單片機(jī)PIC18F1320為核心設(shè)計信號采集電路，實現(xiàn)了信號的采集和保存。系統(tǒng)采用串行電可擦除芯片24LC32A保存數(shù)據(jù)，經(jīng)過有線通信，信號數(shù)據(jù)由串行口通過MAX232芯片輸送到微型計算機(jī)接收和保存，最后繪制出信號波形。 微型計算機(jī)程序采用Visual Basic編程。研究成功采樣頻率為3 kHz的復(fù)雜信號，證明該方案符合設(shè)計要求。
Abstract:
Portable signal acquisition is useful in machine health monitoring systems. The signal characteristics of machine health monitoring includes low frequency signals. The goal of this study is to realize simple, inexpensive and portable low frequency signal sampling. This paper provides the project of signal acquisition system design based on PIC18F1320 microcontroller manufactured by the MicroChip Technology Incorporation to achieve signal sampling and storage. The system adopted EEPROM 24LC32A to store the signal data. The microcomputer received data via wired link with the MAX232 IC through the serial port. The microcomputer program, programmed in Visual Basic, received the data, stored it and plotted the signal. The study successfully samples 3kHz complicated signals and thus meets the design requirement.
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.
為提高電容測量精度，針對電容式傳感器的工作原理設(shè)計了基于PIC16LF874單片機(jī)電容測量模塊。簡單闡述了電容測量電路的應(yīng)用背景和國內(nèi)外研究現(xiàn)狀，介紹了美國MicroChip公司PIC16LF874單片機(jī)的特性。電容式傳感器輸出的動態(tài)微弱電容信號通過PS021型電容數(shù)字轉(zhuǎn)換器把模擬量數(shù)據(jù)轉(zhuǎn)換成數(shù)字量數(shù)據(jù)，所測數(shù)據(jù)由PIC16LF874單片機(jī)應(yīng)用程序進(jìn)行處理、顯示和保存。實驗結(jié)果表明，固定電容標(biāo)稱值為10~20 pF 的測量值相對誤差在1%以內(nèi)，同時也可知被測電容容值越大，測量值和標(biāo)稱值相對誤差越小。
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.
簡介
紅外通信是實現(xiàn)兩臺設(shè)備間無線、點對點通信的一種低成本方法。成立于1994年的INFRARED DATA ASSOCIATION(常簡稱為IRDA）致力于開發(fā)短距離紅外傳輸通信的標(biāo)準(zhǔn)方法。這些標(biāo)準(zhǔn)已經(jīng)過持續(xù)改進(jìn)，使用日益廣泛。現(xiàn)在，眾多設(shè)備實現(xiàn)了IRDA標(biāo)準(zhǔn)規(guī)范，包括計算機(jī)、打印機(jī)、PDA、手機(jī)、手表和其他儀器。
針對51單片機(jī)系統(tǒng)中常用的A/D轉(zhuǎn)換器價格高、精度低的缺點，介紹TI公司的16 位的帶有I2C串行接口的A/D轉(zhuǎn)換器ADS1110的工作原理，給出ADS1110與AT89C51單片機(jī)系統(tǒng)的接口電路和軟件設(shè)計。實踐證明，ADS1110具有高性價比和實用性。
Abstract:
According to the disadvantages of high expense and low accuracy of the general A/D converter used in MCS51 MicroChip system,the principle and working process of a high accuracy 16-bit A/D conversion ADS1110 which has I2C bus and belongs to TI Company are proposed here as well as the interface of ADS1110 to AT89C51 and software list.It is proved to be high performance index and practicability.
利用Atmel公司的ATmega168微處理器，采用A/D轉(zhuǎn)換方式來實現(xiàn)按摩椅控制器的鍵盤接口，通過在硬件電路中巧妙地選擇電阻，在軟件設(shè)計中采用數(shù)字濾波、二分法和區(qū)間鑒定等方法，靈敏可靠地實現(xiàn)了按摩椅中30個按鍵的處理。給出了硬件電路設(shè)計和軟件設(shè)計思想以及部分匯編代碼。
Abstract:
This paper chooses A/D conversion method to realize the keyboard interface of the controller by using ATmega168 MicroChip from Atmel Company.It accomplishes 30-key dealing sensitively and reliably in massage chair through skillfully selecting resistors in hardware circuit and using digital filter,dichotomy and area-judging method in software design.The hardware design circuit, software design idea and partly assembles code are presented mainly.
提出一種基于單片機(jī)AT89C51SND1C的MP3播放系統(tǒng)的設(shè)計方案。單片機(jī)集成了專用的解碼器，使用K9F1208閃存作為外存儲器，放音電路采用CS4330，存儲文件通過播放器上的USB接口設(shè)備從PC機(jī)上直接下載，液晶顯示采用LCD1602。方案設(shè)計簡單，性價比高，低功耗，易擴(kuò)展。由于采用的是通用單片機(jī)實現(xiàn)的，可以很容易地移植到其他微控制器系統(tǒng)中，有很強(qiáng)的市場競爭能力和實用價值。
Abstract:
A MP3 player design based on MicroChip AT89C51SND1C was presented, which used K9F1208 Flash chip as the memory circuit and used CS4330 as play chip. Storage files were download from PC through USB interfaces player on the device，and the LCD/602 was used as display screen. This system had characteristics of simple design,low power,easy expand，low cost and high recognition. Using of universual MicroChip make it easy to transplant to other microcontrol system，and have strong market competitiom and practical value.
