"In the evaluation of the MCU main control board of Freescale maps four-color board development kit, we learned about the functions of maps-mcu main control board and its simple use. Of course, these are just appetizers. We haven't experienced the unique functions and charm of the four-color board development kit, which inevitably makes people feel more meaningful. However, I believe that after reading today's evaluation, you will have less regrets and more expectations. At present, another board in the maps four-color board development kit is the general peripheral board, which is named maps-dock. Maybe your first impression of it is that it has many functional resources, especially for novices, it may be too complex to start? Is that true? I believe that after reading this evaluation, you will naturally have a measurement standard in your heart.
General peripheral board maps-dock
Different from the Yellow style of maps-mcu main control board, map-dock board adopts the traditional green PCB design, which should be the most style you have ever seen. What really makes the engineers feel that the maps-dock general peripheral board is in contrast to the main control board is the dense electronic components on the board, which almost "captured" the front space layout of the whole board, while the back is just the idea, which can be said to be "poor", as shown in the figure below
The peripheral resources of maps-dock board are very rich, mainly including:
Freescale K20 microcontroller, based on cortex-m4 processor, is used as on-board debugger
One micro SD card slot, one 8Mbit SPI nor flash, one 2kbit EEPROM
I2S audio codec supports one stereo headphone output, two speaker outputs and one microphone input
On board USB debugger supports cmsis-dap protocol and USB to UART function
USB full speed interface, infrared transceiver interface, two UART interfaces and one can interface
One DAC / PWM audio output interface
Two single ended or one differential ADC input
One 128X64 monochrome LCD screen with SPI interface
Four physical keys, four LED displays, one five way key and six touch keys
The biggest feature of maps-dock general peripheral board can be said to be comprehensive. It basically includes various functions that can be realized by a microcontroller, such as audio, microSD, USB, SPI flash, EEPROM, LCD, can, PWM, IR, RS232, RS485, etc. However, it is also because of so many functions that beginners feel that the board is too complex and difficult to start. What consensus is more common?
The author also tried to consider the purpose of this design from many aspects, but found that it seems to be a bit of "cutting corners". How to say, if you jump out of the limited thinking of maps-dock board and look at the whole map four-color development kit, you will find that maps-dock is only a function expansion board, which can not be used alone or become a burden for your development. When you want to use some functions, it is easy to connect it to the MCU main control board.
Of course, the maps-dock function board is not omnipotent. Some functions on the board cannot be realized at the same time. There are multiplexes between many signals, such as the three USB interfaces in the figure below, including two micro B types (one USB device function, one K20 debugging signal) and one type A (USB host function)
The USB host function and device function are multiplexed, so only one function can be realized at the same time. In addition, maps-dock can supply power through the on-board USB debugger interface or from the interconnected maps-mcu main control board, but it can not supply power through the microusb interface reused with the USB host function, which engineers should pay attention to when developing.
In fact, if it is just these functions, Freescale can transplant all functions to the same board, adopt separate design, and specially design the unique PM interface carried on the board (the definition of PM interface can refer to the hardware document, as shown in the figure below). What is the purpose?
In the evaluation of the maps-mcu main control board, we have introduced the MPM interface on the MCU board, and the map-dock board is equipped with a hole PM connector, which is also called FPM interface here. MPM and FPM can be well combined to realize the control of the MCU main control board over the function board, and engineers can use the on-board debugger of the function board, The debugging of the main control board is realized without the intervention of a third-party simulator.
Is this separate design just for "tall"? Of course not. I believe that friends who read an evaluation before Aiban can easily think of the original design intention of the four-color board - to build an open-source hardware platform. Don't forget that maps four-color boards are not only maps-mcu main control board and maps-dock general peripheral board, but also bridge board and professional application board. These boards are connected with the main control board through a unique PM interface to form an easy-to-use, portable and open development platform. Through another expansion board, we can also access Freescale's frdm platform Access to Arduino extension platform, which is a new open source platform and can accommodate more and more open source hardware projects. Is it worth looking forward to!
Maps four color palette purchase address:
MAPS【KS22+DOCK】： https://www.eeboard.com/shop/?c=products&a=view&id=3837
MAPS【KL43+DOCK】 : https://www.eeboard.com/shop/?c=products&a=view&id=3838
MAPS【K22+DOCK】 : https://www.eeboard.com/shop/?c=products&a=view&id=3836
Introduction to development environment
The development environment is mainly divided into hardware development tools and software ide tools:
Hardware development tools
From the board, we can see that both boards provide 20pin standard JTAG interface. We can directly program and develop MCU through third-party simulators such as j-link and ulink2.
Of course, if you can only develop with the help of third-party tools, the functions of the board are too low. How to talk about the open-source essence of ready to use and simple aspects. Therefore, another way is to develop directly through the microusb interface connecting K20 microcontroller on the maps-dock function board.
We are no stranger to K20 as an on-board debugger. On the frdm-kl25z platform, we first came into contact with the birth of the cross era opensda debugger, but the first generation is not open source. In the freedom frdm-k22f board we evaluated earlier, the opensda debugger has been updated to v2.1 and is based on the open source cmsis-dap protocol of arm, As a development kit for the open source platform, the maps four-color suite is also based on the open source cmsis-dap protocol. It is quite convenient to use in practice. Some drivers that need to be installed will be described in detail in the power on link later (it must be described in detail, which must be criticized. The driver installation tutorial provided by the official is very deceptive).
Software ide tools
As a development kit for open source platform, we can see the shift of Freescale's product strategic thinking. In the provided software development package, we do not first promote the routine code of our own ide such as KDS and CodeWarrior, but mainly promote the routine source code of third-party ide tools such as keil and IAR, This allows more engineers to use it and reduce learning costs. From such changes, we can also see Freescale's determination to promote the open source platform. In actual use, it is recommended that you use keil 5.11 or above and IAR 7.2 or above.
Power on use
As a function expansion board, maps-dock is not equipped with a master MCU, so it cannot be developed alone. During development, we need to match the maps-mcu master board in the previous evaluation to realize complete development, that is, the current development environment is mainly around Freescale k64 microcontroller. The board can be powered through the debug microusb interface on the master MCU board or maps-dock peripheral board, as shown in the power topology in the figure below
Drive installation
Connect the computer to power on through the debugger interface of mpas-dock board. When Windows executes automatic installation of driver, it will prompt that the installation fails. Here comes the place where people are cheating. At this time, if you operate according to the user guide provided by the official, you should find the driver mbedwinserial.zip under the tools folder in the maps software development package, and then unzip it to manually execute the installation. However, there is no driver in the software package downloaded by the author. Is it wrong to open it!!!
After tossing and turning for a long time, it's still wrong. Finally, I found the mbed windows serial port driver on the armmbed page based on the inspiration of driver naming. During the installation process, the board needs to be connected and powered on.
After installing this driver, a new situation occurs, a USB_ CDC drive, as shown in the figure below. If you don't know Freescale's opensda debugger, I believe you can jam most engineers here.
The author tried to enter the bootloader mode of maps development kit (press and hold the reset button of the main control board and power on at the same time), and re burned the firmware 0221_ k20dx128_ k64f_ 0x5000.bin, after burning, plug in and power on again, and finally see the mbed serial port (as shown in the figure below). At this time, the board can support cmsis-dap debugging. Here, we can officially develop the maps four-color suite.
Maps four color palette purchase address:
MAPS【KS22+DOCK】： https://www.eeboard.com/shop/?c=products&a=view&id=3837
MAPS【KL43+DOCK】 : https://www.eeboard.com/shop/?c=products&a=view&id=3838
MAPS【K22+DOCK】 : https://www.eeboard.com/shop/?c=products&a=view&id=3836
Developed through keil 5.14 ide tool
The IDE development tool selected by the author here is keil v5.14. If you are a friend who contacts Freescale k64f microcontroller for the first time, you need to install the database of the corresponding microcontroller for keil 5.0 or above, as shown in the figure below
In fact, the software development package provided by Freescale is very rich in data. It provides software support for Freescale k64f kernel and peripherals (except for the original driver, I don't know where to go), including the hardware abstraction layer Hal of the device, device drivers and routines based on Hal. In addition, the software package also includes the latest RTOS kernel, USB protocol stack and other software modules are used to expand and enhance the functions of maps four-color board development kit.
In the demos folder, you can see rich routine code resources, but many routine resources exceed 32KB. Engineers using ide tools with 32K code space should consider upgrading the software.
Here, the author randomly selects a routine to load, such as RTC_ Func, you can see that the loaded routine contains the device driver library project file and the routine code project file. Because the routine needs to use the device driver library of maps to call Hal and peripheral drivers, we need to build the device driver library KSDK of maps before compiling the routine_ platform_ Lib. A, click KSDK_ platform_ The lib. A project file is compiled, as shown in the following figure
ksdk_ platform_ After the lib. A device driver library file is compiled, execute the compilation of the routine
After the routine is compiled, you can select the corresponding debug tool. We debug through the onboard microusb interface, so the cmsis-dap debugger is selected here
After downloading, we can view RTC through serial port_ Output of func
As shown in the figure below, the LCD display function of maps-dock is realized through SPI signal
Of course, friends who need to perform the debugging function can directly use the debug button (crtl + F5), as shown in the following figure
The experience of more resources and routines about maps four-color development kit will not be demonstrated one by one in this article. Interested engineers can buy one and have a personal experience. At present, the price of the kit in aibanwang mall is 278rmb / set.
Summary
This paper introduces the functional characteristics of maps-dock general peripheral board in maps four-color board development kit, and realizes the demonstration of some functions of MCU by cooperating with maps-mcu main control board. From the structural layout of the whole maps four-color board development kit, it is not difficult to see Freescale's determination to open source platform:
The main control board is designed calmly, almost a simplified minimum system, which is convenient for expansion and DIY;
The maps-dock peripheral board has complete functions, almost including most general peripheral resources, and can basically test most common interfaces of microcontrollers;
The professional application board is for specific applications, such as motor drive, Internet of things applications or wireless charging, etc;
The bridge board is compatible with various popular development platforms on the market, such as frdm platform, Arduino platform, raspberry pie and so on
The maps four-color board development kit will successively produce a series of main control boards and expansion boards of various MCU, which can truly realize low cost, strong scalability, wide compatibility and easy transplantation. It can not only meet the differentiated needs of engineers, but also suitable for all users who need to learn and apply Freescale MCU products.
Finally, we can use one sentence to form
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