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, Email:firstname.lastname@example.org
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
Acquisition Board 1
ARM9 system boardWeb Server
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
STATUS, 02 READ INPUT STATUS, 03 READ HOLDING
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.
 Xiangqing Liu and Hanxu Sun, “Data Acquisition System of Acceleration Based on ARM7”. Microcontrollers & Embedded Systems, Dec, 2010.  Kunyu Sun and Xuelei Sun, “Remote Monitoring and Control System for Bio-fermentation Process Based on ARM9”. Instrument Technique and Sensor, Feb, 2010.  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.