By Vanessa Snyder,2014-05-17 16:25
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    The Common Data Acquisition System Based On Arm9

    Jiannong Wang, Wei Wang

    ChangZhou Institute of Technology

    Tongjiangnan Street 299, 213022 ChangZhou, JiangSu, China

    Phone: 0519-85567950,

    which is an important branch of computer applications, is an Abstract Embedded technology and people's lives have been closely

    related, but traditional data acquisition system only responds to integrated application of technology, based on sensors, signal particular signals, which is quite limited. A newly- designed idea is measurement, data processing and embedded systems. proposed in this paper with ARM9 processor as the core components, Because of a wide variety of signals of measured object (eg. to design a common data acquisition system. We just need to use electrical parameters of current, voltage, power, frequency, different data acquisition board according to different signals, to analog, circuit breaker status, digital signal protective actions, form a user-defined data acquisition system conveniently, flexibly the amount of electrical pulses degree, non-electrical and fast. Hardware structure is made up of Web Server, ARM9 system Parameters of temperature, pressure and other thermal signal, board and the multi-block STM8L data acquisition board. With linux water level , flow and other hydraulic signal; pulse, ECG, as its operating system, ARM9 system board, based on the Qt

    speed and other signals), the usual practice is to design special platform, develops the application program and completes the

    corresponding tests. data acquisition systems according to different signals, and

     thus, there are some limitations.

    Keywords Data Acquisition, ARM9, Qt, MODBUS, STM8L Therefore, we propose to build a universal data acquisition

    system consisting of hardware and software platforms, based

    I. INTRODUCTION on ARM9 microprocessor core. We just need to choose

    different data acquisition boards according to different Embedded computer technology, as an important part of measured signals, and then a user-defined data acquisition computer field, is closely related to people's lives and has system can be formed conveniently and flexibly. become hot in research and application area. Data acquisition,

    system board and the multi-block STM8L data acquisition

    board, as is shown in Figure 1. The system uses a distributed II. ARCHITECTURE OF SYSTEM HARDWARE

    architecture, and hardware and software are designed as

    modular. Universal data acquisition system hardware is composed of

    the overall structure of Internet layer, monitoring layer and

    data collection layer, and is made up of Web Server, ARM9

    Data collection layerMonitoring layerInternet layer

    STM8L Data

    Acquisition Board 1

    ARM9 system boardWeb Server

    STM8L Data

    Acquisition Board n

     Figure.1. Common Data Acquisition System Architecture

    128MB NAND FLASH, etc.), LCD interface, touch screen

    interface, USB Interface, SD card interface, 100MHz network A. ARM9 System Board Structure

    interface, GPRS interface and three UART interfaces. System

    board structure is shown in Figure 2. The system board is made up of the ARM9 processor

    modules (including the S3C2410, 128MB SDRAM and

    100M Ethernet UART1Power ModuleGPRSport

    UART2USBARM9 Processor Module

    UART3LCDTouch ScreenSD Card

     Figure.2. ARM9 Board Structure.

    ARM9 processor module, the core of the system, based on interface and GPRS interface are for remote data the Linux operating system, makes the management of system communications with the Web Server, UART1, UART2 and I/O device, file management, and data transmission and UART3 STM8L data acquisition board are used for data processing possible. LCD and touch screen is mainly used for communication with STM8L data acquisition board or other human-computer interaction, collected data display and data communications between the modules (such as RFID mapping data collection curve; USB interface and SD card module, GPRS module, GSM module and the ECG module, interface are for capturing data file storage; 100MHz network etc.).

    STM8L152C6 chip 12-bit ADC 25 can meet most of the

    needs of the conversion requirements of accuracy and the B. STM8L Data Acquisition Board Structure

    number of channels, in addition, other resources on the chip

    can also meet the demands of data collection. STM8L data acquisition boards are composed by the

    2. Features of AD202 Features STM8L MCU, sensor interface, filter amplifier, UART

    AD202 is a transformer coupled, micro-encapsulated interface of components, as shown in Figure 3.

    precision isolation amplifier, with features of high precision,

    low power consumption, common mode performance, small Sensor InterfaceUARTsize and low price. It makes electrical isolation of the input and

    output signals possible through the on-chip transformer

    coupling. On-chip DC voltage conversion circuit can provide

    ? 7.5V/2mA the isolated power supply for input stage,

    external sensors and signal processing circuit, optimizing the

    design of peripheral circuits to improve the cost-effective chip. Filter AmplifierSTM8L MCUAD202 is widely used in multi-channel data acquisition

     system, current short-circuit measurement, motor control, Figure.3. STM8L Data Acquisition Board Structure. signal processing and isolation and low drift input amplifier Sensor interface is used to transform the sensor signal (such and so on. as bridge circuits, I / V circuit, etc.); as to filter amplifier, Select AD202 is intended primarily to consider the AD202 isolation amplifier is selected for isolation and isolation of the sensor signal amplification, also can be amplification of the signal filter, and transfers it to the ADC isolated from the post-stage circuit to provide power, thereby STM8L end; STM8L MCU (ST companies’ STM8L152C6) reducing interference and ensure the accuracy of the ADC as the core of the acquisition board, is used to acquire and conversion. transmit front-end signal to the ADC; UART interface is for

    communicating between data acquisition board and ARM9 ?.ARCHITECTURE OF SYSTEM SOFTWARE system board (using the MODBUS communication protocol).

    1. Features of STM8L152C6 The architecture of universal data acquisition system STM8L152C6 core component is STM8, 16MHz software, which is divided into Internet layer, monitoring layer frequency, 1.8V ~ 3.6V voltage (it can still work when power and data collection layer three layers, Internet layer of Web supply is down to 1.65V); memory to 32K Flash, 2K SRAM, Server, monitoring layer of ARM9 system board and data 1K EEPROM; 4 ultra-low-power mode, built-in RC oscillator ; collection layer of multi-block STM8L data acquisition board 25 Road, 12-bit successive approximation ADC, including a using different software platforms design. road fast channel switching time is 1μs, 12-bit DAC

    conversion time 1μs, ultra-low power comparator.

    the cyclic redundancy check code (CRC) information. All A. Internet layer of software functionality

    other STM8L data acquisition board can see this message, but

    only the address is specified STM8L data acquisition board Internet layer (Web Server) using ASP.NET and SQL

    will respond. Server software development platform, including collection of

    Device address is a number from 0 to 247, STM8L data data processing , database management (historical database),

    acquisition board address can be preset. STM8L function code exception handling, statistical calculations and reports,

    defines the data acquisition board should implement a performance analysis and operation guidance and so on.

    command, such as reading data, receive data, status reports

    and so on. Function code number from 1 to 255 (MODBUS B. Monitoring Layer Software Platform Built and Application

    function code with up to 255, usually: 01 READ COIL Modules


    REGISTER, 04 READ INPUT REGISTER, 05 WRITE Monitoring layer software (ARM9 system board) with

    SINGLE COIL, 06 WRITE SINGLE REGISTER, etc. .) Linux operating system, development and design environment

    Function defines the data to read the address, including the based on Qt. Major application modules: host MODBUS, data collected and the value stored in memory, or other parameter settings (STM8L data acquisition board address, the function code according to the requirements of the information acquisition cycle, acquisition channel, etc.), real-time data needs to be executed. CRC generated by the ARM9 system communications, real-time graphical display, local data board, and the data acquisition board by the STM8L check, if storage, data retrieval, exception handling, historical data

    the CRC does not match, it will request retransmission of communications (with the Web Server rooms) and so on.

    information. When STM8L data acquisition board 1. Construction of Linux operating system

    implemented the required functions, it will return a message to When the operating system is built on ARM9 System board,

    the ARM9 system motherboard, the return message contains we need to transplant the bootloader, Linux kernel and file the address of STM8L data acquisition board, the required system: Vivi is used as the system bootloader; Linux-2.4.18 is function code, the required data and a CRC value. used as the system kernel; YAFFS is used as the file system, 4. Qt Application Design YAFFS is designed for embedded systems using NAND-type As to Qt application design, we should first design Qt flash memory which is a log-based file system.

    application programming interface (menus and buttons, etc.), 2. Construction of Qt Development Environment

    design each application module, and connect the signals of Qt is a cross-platform application framework, application

    module functions and slots. Signals and slots are Qt and user interface can be developed by Qt. Building Qt is to

    application-specific communication mechanism and are a run the Qt application on the ARM9 system board. It should

    include the source code package: e2fsprogs-libs-1.37.tar.gz, response (slot) to user action (signal). Signal and slot libjpeg-iwmmxt.tar.bz2, qt-embedded-2.3.10-free.tar.gz, connection statement format:

    Connect (sender, SIGNAL (signal), receiver, SLOT (slot)); qtopia-free-source-2.1.1.tar.gz, qt-x11-2.3.2.tar.gz,

    qt-x11-free-3.3.4.tar.bz2, tmake-1.1.3.tar.gz, tslib.Tar.gz. For example,

    According to a certain order to compile these source codes to Connect (RD, SIGNAL (clicked ()), this, SLOT (rad ())); generate the required documents which are copied to the //RD button is pressed, the rad slot is response, the rad () specified directory on ARM9 system board. Modify the script function is executed

    file, add qpe order to make ARM9 system board can start Qt Connect (timer0, SIGNAL (timeout ()), this, SLOT applications at boot time. (flushBuff ()));

    3. MODBUS Communication Protocol //timeout signal transmission, flushBuff slot is response,

    flushBuff () function is executed) MODBUS protocol is applied to the controller of a

    communication language. Through the MODBUS protocol, The test program interface of Real-time data between the controllers, the controller and other devices communications and real-time graphics display are shown in through the network can communicate. MODBUS is to use a Figure 4.

    standard RS-232C serial interface, the controller can directly network. Using the master-slave controller communication

    technology, in which only the master can initiate the transfer (query). Other main equipment from the equipment according

    to data provided to respond to queries. MODBUS ASCII and

    RTU protocols can use two modes of communication.

    ARM9 system board data acquisition board with STM8L

    used between the MODBUS RTU protocol communication

    pattern, ARM9 system board as the main equipment, STM8L

    data acquisition board as a slave device. ARM9 system board from a STM8L want to get the data Figure.4. Collected by the Sine Wave Signal acquisition board, when, ARM9 system board will send a

    containing device address, function code, the required data and

C. Data Collection Layer Software Modules

    Data collection layer software is based on the software environment of IAR Embedded Workbench, with C++

    Compiler and STM8L15x_StdPeriph_Driver Programming. The main software modules include: slave computer MODBUS, parameter setting (acquisition board address, the acquisition cycle, acquisition channel, etc.), ADC, digital filtering, real-time data storage, real-time

    data communications and so on.


    The common data acquisition system which is proposed in this paper has achieved some features of monitoring layer and data collection layer (Complete the construction of ARM9 system board hardware and software environment; implement the design of STM8L acquisition board; design such application modules as host MODBUS, slave MODBUS, parameter setting, real-time data communications, real-time graphical display, local data storage, ADC, digital filtering and so on). Judging from the system test, it can achieve the desired effect, and especially, STM8L ADC data acquisition board is highly precise and consumes low power. Besides,

    the ARM9 system

    motherboard with multi-block STM8L data acquisition board can also constitute the system independently, which makes the system constitution common, flexible and convenient.


    The author wishes to thank the IEEE for providing this template and all colleagues who previously provided technical support.


    [1] Xiangqing Liu and Hanxu Sun, Data Acquisition System of Acceleration Based on ARM7”. Microcontrollers & Embedded Systems, Dec, 2010. [2] Kunyu Sun and Xuelei Sun, Remote Monitoring and Control System for Bio-fermentation Process Based on ARM9. Instrument Technique and Sensor, Feb, 2010. [3] Zhenglin Yu and Long Zhang, Modbus Communication Protocol Based on FPGA. Modern Electronics Technique, Nov, 2010.


    Jiannong Wang was born in Nantong, in 1958.He received MS from

    in 1982.Now he is a professor in ChangZhou HuNan University

    Institute of Technology. His research interests include embedded system, data processing etc.

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