便攜式信號采集在機器健康診斷系統中有較高的應用價值。機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簡易而且低成本的低頻便攜式信號采集。以Microchip公司單片機PIC18F1320為核心設計信號采集電路，實現了信號的采集和保存。系統采用串行電可擦除芯片24LC32A保存數據，經過有線通信，信號數據由串行口通過MAX232芯片輸送到微型計算機接收和保存，最后繪制出信號波形。 微型計算機程序采用Visual Basic編程。研究成功采樣頻率為3 kHz的復雜信號，證明該方案符合設計要求。
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.
為解決輸油管道溫度壓力參數實時監測的問題，設計了以C8051F930單片機作為控制核心的超低功耗輸油管道溫度壓力遠程監測系統。現場儀表使用高精度電橋采集數據，通過433 MHz短距離無線通信網絡與遠程終端RTU進行通信，RTU通過GPRS網絡與PC上位機進行遠程數據傳輸，在上位機中實現數據存儲和圖形化界面顯示，從而實現輸油管道溫度壓力參數的實時監測和異常報警。經實驗證明，該系統的12位數據采集精度滿足設計要求，漏碼率小于1%，正常工作時間超過5個月，能實時有效地監測輸油管道的溫度壓力參數，節省大量人工成本，有效預防管道參數異常造成的經濟損失和環境污染。
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.
The bootloader is stored in the internal boot ROM memory (system memory) of STM32devices. It is programmed by ST during production. Its main task is to download theapplication program to the internal Flash memory through one of the available serialperipherals (USART, CAN, USB, etc.). A communication protocol is defined for each serialinterface, with a compatible command set and sequences
This example provides a description of how to use the USART with hardware flowcontrol and communicate with the Hyperterminal.First, the USART2 sends the TxBuffer to the hyperterminal and still waiting fora string from the hyperterminal that you must enter which must end by '\r'character (keypad ENTER button). Each byte received is retransmitted to theHyperterminal. The string that you have entered is stored in the RxBuffer array. The receivebuffer have a RxBufferSize bytes as maximum.
The USART2 is configured as follow: - BaudRate = 115200 baud - Word Length = 8 Bits - One Stop Bit - No parity - Hardware flow control enabled (RTS and CTS signals) - Receive and transmit enabled - USART Clock disabled - USART CPOL: Clock is active low - USART CPHA: Data is captured on the second edge - USART LastBit: The clock pulse of the last data bit is not output to the SCLK pin
This code implements the basic functions for an I2C slave device using the SSP module. All I2C functions are handled in an ISR. Bytes written to the slave are stored in a buffer. After a number of bytes have been written, the master device can then read the bytes back from the buffer.
SDP Search and Record generator
OVERVIEW:
Recognizing the difficulty in creating an SDP service description and search
from scratch, Microsoft is providing a sample utility in bthnscreate.cxx to
automatically create a service or record. This utility can be run to create
an SDP record or to setup an SDP Service, Attribute, or ServiceAttribute
search based on information stored in a human readable file.
用LPC213X系列的PWM來產生語音。語音數據來源于PC機轉換后得到的。最大可以是16位的。
由于是PWM所以輸出端口需要低通濾波才能夠得到比較干凈的聲音。
可以經過修改使用LPC2132以上的ARM的D/A來產生。
This project outputs audio on PWM0 using wave samples that are stored in the on-chip Flash ROM.
內容如下：
1.The history of the computerized database
2.SQL Data Statements--those used to create, manipulate, and retrieve data stored in your database example statements include select, update, insert, and delete
3.SQL Schema Statements--those used to create database objects, such as tables, indexes, and constraints
4.How data sets can interact with queries
5.The importance of subqueries
6.Data conversion and manipulation via SQL s built-in functions
7.How conditional logic can be used in Data Statements
The tar file contains the following files:
ptfsf.c: heart of the perfect TFSF code
ptfsf.h: header file for same
ptfsf-demo.c: FDTD code which demonstrates use of perfect TFSF code. Essentially this program used to generate results shown in the paper
ptfsf-file-maker.c: code to generate an incident-field file using the "perfect" incident fields
ptfsf-demo-file.c: FDTD code which uses the perfect incident fields stored in a file
fdtdgen.h: defines macros used in much of my code
Makefile: simple make-file to compile programs
Also include are some simple script files to run the programs with reasonable values.
The code assumes a two-dimensional computational domain with TMz polarization (i.e., non-zero field Ez, Hx, and Hy). The program is currently written so that the incident field always strikes the lower-left corner of the total-field region first. (If you want a different corner, that should be a fairly simple tweak to the code, but for now you ll have to make that tweak yourself.)
Routine mampres: To obtain amplitude response from h(exp(jw)).
input parameters:
h :n dimensioned complex array. the frequency response is stored
in h(0) to h(n-1).
n :the dimension of h and amp.
fs :sampling frequency (Hz).
iamp:If iamp=0: The Amplitude Res. amp(k)=abs(h(k))
If iamp=1: The Amplitude Res. amp(k)=20.*alog10(abs(h(k))).
output parameters:
amp :n dimensioned real array. the amplitude-frequency response is
stored in amp(0) to amp(n-1).
Note:
this program will generate a data file "filename.dat" .
in chapter 2
