STM32, literally understood, ST is STMicroelectronics, M is the abbreviation of Microelectronics, and 32 means 32-bit. Taken together, STM32 refers to the 32-bit microcontroller developed by ST. Among today's 32-bit controllers, STM32 can be said to be the brightest new star. It is flattered, favored by engineers and the market, and can be better without a core.
51 is an entry-level classic MCU in embedded learning. Because of its simple structure, easy to teach, and can be programmed through the serial port without the need for additional simulators, it has been widely used in teaching. So far, many universities have used embedded 51 is used in teaching. 51 was born in the 1970s and belongs to the traditional 8-bit single-chip microcomputer. Nowadays, the baptism of years has both its glory and its shortcomings. Product competition in the current market is becoming increasingly fierce and extremely cost-sensitive. Accordingly, MCU performance requirements are more stringent: more functions, lower power consumption, easy-to-use interface and multitasking. Faced with these requirements, 51 existing resources seem to be stretched. Therefore, whether it is college teaching or market demand, a new MCU is urgently needed to inject new vitality into this field.
Based on this market demand, ARM has launched its new 32-bit Cortex-M3 microcontroller core based on the ARMv7 architecture. Immediately afterwards, ST (STMicroelectronics) introduced the MCU-STM32 based on the Cortex-M3 core. With its diversified product line, high cost performance, and easy-to-use library development method, STM32 quickly stood out among many Cortex-M3 MCUs and became the brightest new star. STM32 quickly occupied the middle and low-end MCU market as soon as it went on the market, and was extremely favored by the market and engineers, and it was quite sparkling. To become a qualified embedded engineer, we are not deaf to the new emerging technologies, but to meet the needs of the market as soon as possible and keep up with the trend of technology. Now the emergence of STM32 is a trend, a trend, what we have to do is to get on this express train to make our technology more competitive.
STM32 is a microcontroller, with various common communication interfaces, such as USART, I2C, SPI, etc., can be connected to a lot of sensors and can control a lot of devices. In real life, many electrical products we come into contact with have STM32 figures, such as smart bracelets, micro quadcopters, balance cars, mobile POST machines, smart rice cookers, 3D printers and so on.
STM32 has many series, which can meet the various needs of the market. There are Cortex-M0, M3, M4 and M7 from the core. Each core is roughly divided into mainstream, high performance and low power consumption. See Table 1 for details.
Table 1 STM8 and STM32 classification
From a purely learning perspective, you can choose F1 and F4. F1 represents the basic type, based on the Cortex-M3 core, with a clock speed of 72MHZ, and F4 represents high performance, based on the Cortex-M4 core, with a clock speed of 180M. For F1 and F4 (above 429 series), in addition to the different cores and the improvement of the main frequency, the obvious feature of the upgrade is that it has an LCD controller and camera interface, and supports SDRAM. This difference will be given priority in project selection. However, from the perspective of university teaching and user beginners, the F1 series is still the first choice. At present, the STM32 of the F1 series has the most information on the market and the largest product share.
STM32 naming method is as follows:
After understanding the classification and naming method of STM32, you can roughly choose what kind of core MCU according to the specific needs of the project. For ordinary applications, you generally choose the F1 series of Cortex-M3 core if you want to pursue high performance. , Need a lot of data calculation, and need an external RGB large screen, choose the F429 series of Cortex-M4 core. After clarifying the general direction, the next step is to subdivide the selection. First determine the pins. The more pins will have more functions and the price will be expensive. The specific functions need to be used in the actual project. After determining the number of pins, select the FLASH size. MCUs with the same pin number will have different FLASH sizes to choose from. This is also selected according to actual needs. If the program is larger, choose a larger FLASH. If the product is mass-produced All the savings are money. Some products whose monthly shipments are KK (millions of magnitude) are not only MCUs, but even resistors and capacitors can be used as little as possible, and even the number of PCB vias is particular. The selection of the components in the project has a lot of knowledge.