"The opportunities and challenges brought by the Internet of Things are concentrated in a" fast "word. From 2015, wear bracelets have arrived until the highest peaks are less than a year, and 2016 can wear bracelets in the system has become increasingly Representing a more high-end fashionable smart watch lead high-end wearable market. Both have its own inevitable attributes, bracelets in low prices and entry-level functions, but features single, weak ductility It is a fatal defect; while smart watches conquer users with rich features and excellent experiences, but expensive prices are not enough. It is foreseeable that there will be a narrow but wide mid-user demand market between these two. There is an advantage that there is a long-awaited, and there must be an advantage of fairness and prices. It has the advantage of smart watch features, and has strong practicality. To this end, the pavilion is carefully selected from a variety of popular low-power high-performance microcontrollers. One is just right, the length of the two, can solve the user's pain point-screen display can wear equipment solution, from the latest STM32L4 + series MCU, the latest STM32L4 + series MCU, at the same time, the pavilion has also got its corresponding evaluation board Nucleo-L4R5zi .
Like all Nucleo series cards, Nucleo-L4R5Zi can also be regarded as the smallest system board + detachable ST-LINK / V2-1 debugger combination based on STM32L4 + series MCU. The structure is very simple, for customizes Flexible development is very convenient.
In fact, for the Nucleo board itself, there is really nothing to say, even if the person in contact is, it will be clear. On the Nucleo-L4R5ZI board, in addition to the microcontroller, the debugger, the ST ZIO and the St Morpho extended interface, that is, the USB OTG interface that is taken from the microcontroller characteristics.
The front black extension of the board is ZIO extension interface and is compatible with the Arduino UNO expansion interface. The two-row lead apertures next to ZIO are the St Morpho extension interface, which leads to all IO ports of the board microcontroller, which is convenient for developers to DIY when evaluating the microcontroller.
↓ USB OTG interface, which should be based on the characteristics of the board microcontroller, and some series of microcontrollers support Ethernet, and the Ethernet interface will also be expanded. Two buttons, user buttons, and reset buttons.
↓ Onboard ST-LINK / V2-1 debugger, support the microcontroller programming of the board microcontroller and the ST other series.
↓ Nucleo-L4R5Zi development board, ST brand new STM32L4 + series MCU, specific model is STM32LT5ZIT6, using LQFP144 package, big is all the characteristics you see by you first, if you want to be worn in space Used on the networked device, ST also has other package series, such as WLCSP, UFBGA, meets the needs of all small size applications, and LQPF packages are only suitable for the previous development commissioning or to spatially irritated applications.
At present, the main product lines of the ST STM32L4 + series include: STM32L4R5 / S5, STM32L4R7 / S7 (with TFT interface) and STM32L4R9 / S9 (having MIPI-DSI and TFT interfaces). Regarding the specific parameters of the microcontroller, it will not be used. If you want to know, you can go directly to the ST official to check the relevant specifications. Here is only a few important features, or lift points.
Although it is said that the microcontroller on the board is a low-profile in the STM32L4 + series according to the specification model, but it is not too disappointed. The core function is not absent, and the MCU of other friends, STM32LT5ZIT6 is still performance and function or Comparative. Even compare ST own previous generation L4 series products, L4 + improved numerous functions and performance under the premise of maintaining ultra-low power, such as:
Cortex-M4 processor performance improvement, up to 120MHz frequency, nearly 50% increase in 80MHz of L4
Integrated more internal storage, support 2 MB Flash and 640 KB SRAM
The STM32L4 + series is more submerged in graphics processing capabilities and control, except for the two-dimensional image hardware accelerator Chrom-Art, also integrates a CHROM-GRC graphic storage manager, integrated TFT, DSI graphics controller
Rich and excellent connection features, support USB OTG, supporting higher data transmission 8-line SPI
If you don't make a mistake, the Chrom-GRC Graphic Storage Manager should be on the ST microcontroller, which is also strong, especially for the wearable devices of the circular screen such as smart watches, etc. 20% of storage resources.
Its principle is such that the contrast of the general MCU is displayed on the circular screen, regardless of whether the image is completely displayed on the screen, SRAM will store the pixel point of the entire picture, while the STM32L4 + series of MCUs in the CHROM- The GRC will intelligently store the user-visible image section to the SRAM without storing the user's pixel points, saving SRAM resources. Take a 400 * 400 resolution, 24 bit color deep image as an example, the required SRAM resources are about 469kb space, such as your entire system requires 256kb / left applications, almost 1MB can only be selected when the selection is selected. SRAM's MCU, and if you use the STM32L4 + series microcontroller, 640KB RAM resources are just in line with it, which can be said to be a huge advantage.
In addition, on the STM32L4 + series of products, the two dimensional image hardware accelerator chrom-art is equally processed by the image, in which the CHROM-ART can be reduced when the graphic related application is processed. 70% of the CPU occupied resources, so the Chrom-GRC graphic storage manager + 2D image hardware accelerator chrom-art can be said to be the two swords of the ST STM32L4 + series, especially on the round screen display device, it is a perfect match, Not only reduces SRAM resources, but also reduces the resources of the processor, improve the experience and life, this program is very recommended for the low-end round screen smart watch that pays attention to the cost of the graphical user interface, this program is very recommended.
Another convenient, as a wearable solution, the battery has always been the pain point of the user, even if it is proud of apple watch, although the function is rich, the user experience is good, but its short-lived battery is also a place where the spit is. The ST L series has always been known as low power consumption, this time STM32L4 + under the premise of performance improvement, the power consumption has basically maintained the previous level, and everyone can refer to the table below.
The Nucleo-L4R5ZI board is also the same, and its characteristics are basically surrounded by the STM32L4 + series MCU. For development, the STM32L4 + series MCU is equally flexible, the same constrivificed transplant operation, is compatible with ST different STM32 series is compatible, truly Improve development efficiency for engineers.
Power-on start and development
The St Nucleo Series card is usually taken with a simple lighting program. The program is very common. You can control different LEDs through the user button, at least allow you to detect whether the development board is running normally.
If the board of NUCLEO is used for the first time, it is necessary to install the driver, the most important one is the ST-LINK / V2-1 debugger driver. Installation completion can see the corresponding prompt in device management of the PC. At the same time, we can also see the U disk implemented in the PC side, this is an important feature of the Nucleo series board support ARM Mbed project. It can be seen by the U disk to implement the program. You can see, save The space is 2MB.
The Nucleo-L4R5ZI development environment can be solved with two tools. STM32Cubemx and Keil / Iar are the launched graphical configuration interface for ST. It is used to generate code, convenient, low-cost development difficulty, and the latter is a third party that everyone is familiar. Ide tool. Since the STM32L4 + microcontroller is the latest, if you want to use ST-type code generation tools STM32Cubemx and SDK Download the latest version is better, the latest version is 4.23.
Download address: STM32Cubemx 4.23
4.23 version of CubemX is quite large, such as the scope of the device to screen more refined, and it is worth mentioning that the information of the microcontroller product is integrated, and it can be directly click to view, but in actual use, such as like DataHeet still needs to be downloaded from the server, and the author has not succeeded several times, it seems that the software still needs to be optimized. In addition, we can also see the price of the corresponding microcontroller. The price of this microcontroller on Nucleo-L4R5z is $ 7.45, this price is not judged, at least the cost-effective ranks.
For the developing boards launched by the ST, you can select the card retrieval to locate the corresponding board to be developed in CubemX. L4 + is the latest series of products, so it is very easy to position. There are currently only two boards, one is Nucleo in the hand of the author, and the other is the Discovery series, but unfortunately, the author did not get the descovery you want.
After you select your card, you can see the pin definition diagram including the menu bar, the function bar, the module bar, and the microcontroller, the graphical interface, very intuitive. The interface menu includes a PIN definition, clock configuration, IO configuration, and a function of power estimation.
Configure CubemX based on your own needs, then regenerate the code you need to use, in addition, if you use a third-party IDE tool like KEIL, the software itself needs to be updated, such as Keil to update your own DATABASE.
You can generate the project files you need by graphical tool Cubemx, then compile, download / debug, download / debug, for specific processes through Keil or IAR, this article is no longer, interested in referring to the following procedure.
Low power consumption, large capacity -Nucleo-L496ZG development board evaluation
The most tossible STM32F769 Discovery development board evaluation
Simple, flexible, one to show you unlimited creative products - St Nucleo-F412ZG
The most tossible STM32F769 Discovery development board evaluation
ST CubemX allows users to save new projects, configure, and other columns, novice is not easy to get started, and in the actual experience you can write properly, further improve the efficiency of developers, or very friendly.
In addition, I want to complain that for the peripheral function module that doesn't match the Nucleo series, the Nucleo series card is really tossible unless you have not played the ST microcontroller, then you can Basic SPI, I2C, UART, TM, ADC and other functions begin to learn, and users who are interested in STs are interested in users suggest that they are equivalent to multiplied peripheral modules for multiple configuration points.
summary
The Internet of Things has brought the transformation and upgrading of various industries, and the more demodified markets, the newly launched STM32L4 + series microcontrollers made a targeted optimization, like low-power round screen display product applications. It is a custom-to-one customization. The new L4 + series not only increases the processor's frequency, increasing internal storage, and combines Chrom-ART and Chrom-GRC technology for image processing, and equipped with higher data transmission. 8-wire SPI, additional all kinds of interfaces (support MIPI-DSI and TFT interfaces) and WLCSP, UFBGA, etc., allow it to be sensitive to power consumption, space sensitive, and need simple image processing. Networking applications bring great competitiveness, can be expected that if the primary low-end smart watch series can wear equipment products, STM32L4 + can be a generation of classic smart watch solutions, and wait and see. "
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