"Recently, Aiban has obtained a set of low-cost industrial control evaluation suite core9g25 launched by nuclear wind Intelligent Technology Co., Ltd_ Con, nuclear wind technology is a high-tech enterprise dedicated to producing and selling embedded veneers, CPU core boards and supporting modules based on ARM development platform. While providing embedded hardware solutions, it can also provide customers in embedded application field with software and hardware development tools, complete solutions of embedded systems and customized embedded products and services, According to the past performance, customers in more than 50 countries around the world have received the "blessing" of nuclear wind technology.
CORE9G25_ As a low-cost industrial control board, con evaluation board adopts The core 9g25 core board + backplane architecture of ATMEL at91sam9g25 MPU and the introduction of many peripheral interfaces greatly meet the user's needs for core board function and performance testing. Let's uncover the true face of this evaluation board.
CORE9G25_ Con assessment Kit
Entire core9g25_ The con assessment suite includes:
One core9g25-con motherboard (including core9g25 core board)
A TTL to RS232 serial port module
A cross serial line
One 12V@1A Power adapter for
A DVD disc
Because there is no screen, the TTL to RS232 serial port module attached to this kit is particularly important. The viewing and operation of system startup should be completed through it temporarily. In addition, there is a special place: the power adapter actually obtained by Aiban is 12V@1A And this is the same as the product information description of nuclear wind technology 12V@2A Slightly different, but does not affect the use.
CORE9G25_ Con evaluation board
As mentioned at the beginning of the article, core9g25_ The con evaluation board mainly consists of two parts, which can be simply understood as the core board core9g25 and the base plate core9g25_ Con, the core board is welded on a 130mm * 130mm two-layer PCB base plate in the form of mounting.
CORE9G25_ Front of con evaluation board
CORE9G25_ Con evaluation board resources:
Core board core9g25
Expand 7 TTL level serial ports (6 without pin seat)
One 100m network port (integrated Ethernet transformer), one micro SD interface, one reset button and one user button
Expand 3 USB host interfaces (one of which can support USB client at the same time)
1 12V to 5V DC power supply module
Software support:
Linux 3.6.9 system support with stable and reliable UBI file system
Debian operating system support, which supports the installation of various applications under Debian
It is not difficult to see from the above figure that the core part (core IC) of the whole board is basically concentrated on the core board core9g25, while the backplane only provides power supply module and peripheral interface circuit, which is very concise.
Flip the board (see the figure below) and we can see core9g25_ There is nothing on the back of the con evaluation board, but 4 rows of pinholes are reserved at the core board. It is speculated that diversity interfaces may be reserved for the development of compatible and replaceable core boards in the future.
CORE9G25_ Back of con evaluation board
Core board core9g25
From core9g25_ According to the hardware architecture analysis of con evaluation board, it is not difficult to see that the core board of core9g25, a low-cost industrial control board mainly promoted by nuclear wind technology, is the focus of this content. The core board is a 40mm * 40MM 6-layer PCB with 96pin external interface pins expanded by stamp holes with a spacing of 1.27mm around.
Core board core9g25
Core board onboard resources:
ATMEL at91sam9g25 processor, frequency 400MHz
Samsung 128MB DDR2 SDRAM, Samsung 256MB NAND flash, SMSC 8720A Ethernet PHY
96pin extended processor more features
The core unit of the core board is MPU at91samg25, a highly integrated microprocessor for industrial applications launched by ATMEL in 2011, based on arm926ej-s ™ Core, up to 400MHz main frequency, 15mm * 15mm size, bga217 package.
At91samg25 can support a large number of peripherals, such as FS / HS USB2.0, Ethernet, can, LCD driver, etc. (see the system block diagram of at91samg25 below for details). It also integrates a unique soft modem and is widely used in POS terminal, alarm system, remote care and other occasions; In terms of memory, in addition to the DDR2 and NAND flash we know to be used together on the core board, it supports nor flash and other memories on the market, and can also boot the system from NAND flash and DataFlash.
As for software support, relying on ATMEL's powerful ecosystem, you can get free Android, Linux and windows software packages and evaluation kits to facilitate the evaluation and development of the overall system.
ATMEL at91samg25 system block diagram
Relying on the powerful integration function of ATMEL at91sam9g25 MPU, we can see that the core board core9g25 of nuclear wind technology has a very compact design. Careful users may find that the wiring on the core board often adopts snake wiring in order to pursue equal distance. This wiring method can keep the signal delay difference within a certain reasonable range, Especially in the case of strict timing, this equidistance ensures the synchronization of the clock.
Other circuits of core board core9g25 are common, so we won't discuss them in detail. In addition, the whole core9g25_ The only regret of con suite is that it is not equipped with LCD display module. From the data of ATMEL at91sam9g25 MPU, it is not difficult to find that it is an LCD driver supporting lattice / image, and can support a maximum resolution of 640 * 480, but the whole set of core9g25_ The con Evaluation Kit is only equipped with a serial port level conversion module (see the figure below) to replace the LCD module to check the system startup.
Ttl-rs232 level conversion module
Look at the complete core9g25_ Do you think the hardware composition of con evaluation suite is very concise? In fact, thanks to the rapid development of semiconductor technology and the increasing integration, we can design the development board more exquisite and compact without reducing functions, as shown in the following figure core9g25_ Principle block diagram of con evaluation board.
CORE9G25_ Principle block diagram of con evaluation board
Power on start
Relying on the standardized data sorting on the official website of nuclear wind technology, core9g25_ The power on use of the con evaluation board does not make you feel at a loss at all. Through the information in the attached DVD and the user guide on the official website of nuclear wind technology, both the establishment of the development environment and the starting use of the board become natural.
First, connect the core9g25 evaluation board with the computer serial port through the ttl-rs232 module in the kit, open the serial port tools, such as HyperTerminal, putty, etc. (the serial port tools are also available in DVD), set the serial port tool configuration to 115200,8, none, 1, none, and then power on through the 12V power supply.
Core9g25 evaluation board is powered on and started
After the board is powered on, the red system led near the MPU will change from a slightly bright state to a flashing bright state. At this time, the board is loading the Linux system kernel. After the system is started, you can view the board device and system version through the basic linux commands. The system of the core9g25 evaluation board is a builderoot file system based on the Linux 3.6.9 kernel, We can join the network by plugging in the network cable, or plug in USB devices, micro SD devices, etc. for file access.
However, a problem was also found during the operation of the board. The board will make a "zizizi" sound. It is suspected that it is the resonance sound of devices with plate structure such as ceramic capacitors, tantalum capacitors or inductors on the board. The problem is mainly located on the 12V to 5V DC power supply module. Because it is inconvenient to disassemble and verify, it is difficult to judge which device, This is for the author with abnormal hearing sensitivity, core9g25_ It's hard to start the con evaluation board when it's powered on.
In the figure above, it can be seen that the author has also prepared another notebook computer equipped with Ubuntu system, which is mainly to cooperate with the board development to build a Linux system development environment and add a Linux system development environment for ATMEL AT91SAM Series CPU cross compilation tool, which is core9g25_ The necessary steps for the development of con evaluation board and the construction of specific development environment will not be introduced in detail. Those interested can refer to the construction of Linux development environment on the official website of nuclear wind technology.
For core9g25_ These steps can be roughly summarized in the development of con evaluation board:
Build linux system development environment on PC and compile the program code into core9g25_ Embedded file of con evaluation board
Copy files to core9g25 through mobile storage devices such as USB flash disk and micro SD card_ On the con evaluation board
Core9g25 output from serial port debugging tool_ In the con evaluation board system, execute compiled files through Linux system commands
Next, the author will take the GPIO lighting LED program as an example to demonstrate some functions of the board.
Nuclear wind technology provides the original code of GPIO port in DVD for developers to use and learn from. Here we will directly operate core9g25_ Con evaluation board to demonstrate GPIO functions.
CORE9G25_ The level of all GPIO ports of the con evaluation board is 3.3V. Therefore, in order to vividly show the working condition of the GPIO port, the author DIY an LED display - connect the 330 ohm led in series to the pa22 pin and GND of the board. The pa22 pin is selected mainly because this pin is taken as an example in the source code to save the trouble of modification.
DIY LED display for GPIO function
After power on and startup, we can see that the LED is not lit. At this time, there is no voltage on the pa22 pin measured with a multimeter, and then input the control code through the serial port printing tool, as shown in the following figure.
Input code control GPIO port
Positioning core9g25_ In the / sys / class / GPIO directory of the con evaluation board, call the pa22 GPIO port and assign "1" to the GPIO port of the pa22 signal pin. At this time, you can see that the LED is on (see the figure below), and then assign "0" to turn off the LED. This is also the principle of software controlling the GPIO port in normal circuit operation.
Turn on the LED through the Linux system command
There are more functional routines, such as ad, SPI and I2C, which will not be demonstrated one by one. It is not difficult to find that these operations are quite simple for developers with Linux development foundation. For users who contact this aspect for the first time, they will encounter some problems at the beginning, such as the construction of compilation environment and operation process, At this time, you need to understand each principle and implementation method carefully. I believe that you can be handy after you are familiar with it, and it can be said that it is a once and for all thing for future development and design.
In addition, core9g25_ The operation of updating or restoring the system of the con evaluation board is also very simple. Just put the files to be updated into the USB flash disk or micro SD card, power on and automatically complete the update operation. After the update is completed, remove the mobile storage device, and reset the board is OK. The update results can be observed through serial port printing. The following figure shows the data printed through the serial port of the update system through USB flash disk.
The system is successfully updated through USB flash disk
CORE9G25_ In addition to supporting the built-in buildroot file system and various playing methods, the con evaluation board can also support the Debian file system. However, due to the large system, additional storage must be used, such as starting in the micro SD card. I won't introduce it in detail here. If you are interested, you can refer to the use and development of Debian file system. However, for Debian system, nuclear wind technology only provides system maintenance without technical support. Friends with ideas need to do it themselves.
Finally, let's talk about the author's experience in the past few days. First, core9g25_ The value of con is worth affirming, especially its core board core9g25. With excellent and compact workmanship, numerous function development, perfect development environment and introduction, users with a little foundation can quickly use the data provided by nuclear wind technology. However, with a good grasp of the overall situation, many small details are still insufficient compared with large semiconductor companies, and need to be continuously improved. For example, there is no LCD module with more intuitive display, there will be "zizizi" sound on the evaluation board, most of the resources used are stored in the DVD of the kit, and resources can not be downloaded from the official website, These small details affect the final value of the evaluation suite to some extent.
Summary
Through the core 9g25 of nuclear wind technology_ Through the introduction of the hardware and software features of con development kit and the development environment, we see a core industrial control board with very exquisite workmanship and comprehensive software development. For special fields such as industrial control, stability and reliability can be said to be the first guarantee, The ATMEL MPU at91samg25 selected by nuclear wind technology, which has been tested by the market for many years, is really well intentioned, and I believe it will have a good market performance. However, it is a pity that the details are not perfect, but the price of 188rmb core board is still very attractive, which is almost only 1 / 2 of the price of similar products.
reference material
CORE9G25_ Con evaluation board data
Core9g25 core board data
ATMEL at91samg25 MPU introduction
Original statement: This article is original by Aiban. Reprint is declined“
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