In embedded processors, the use of MCUs is the simplest, but choosing the most suitable one from thousands of MCUs is also a technical task.
Today, Sister Ni will share her valuable experience in selecting MCUs in just 8 minutes.
MCU Selection Skills
Love without the purpose of marriage is just playing around;
Selection without the purpose of the project is just empty talk.
Therefore, the selection of MCUs must start from actual application needs.
In electronic products, the processor chip as the control core is often the most important. As long as the selection follows established criteria, it is basically possible to select a suitable chip.
Different application fields have vastly different performance requirements for MCUs. For example: The working conditions in industrial control are relatively harsh, so high performance, high stability, and high accuracy chips are needed; Chips used in cars need to have a wide temperature range and meet automotive grade requirements due to the heat generated during driving. Therefore, in industrial and automotive electronic applications, choose industrial-grade and automotive-grade chips; if you accidentally choose consumer-grade chips, it will lead to endless troubles.
Specific application requirements determine what resources the MCU should have, for example, what devices the MCU needs to control in the system, what tasks need to be executed; what amount of data needs to be processed, where the signals come from, whether the signals need to be processed; whether external communication is needed, and what communication interfaces are required; whether large storage space is needed or whether expansion is required. In addition, for current products, a very important feature is low power consumption.
From this, it can be seen that if the MCU does not need to process too much data and has no high-speed computing requirements, the performance requirements for the MCU are relatively low, and it needs to have common interfaces such as UART, I²C, SPI; monitoring switch states may require built-in ADC for data conversion.
After the above analysis steps, it is easy to draw a system function block diagram, and the resources that the MCU will use will be clear at a glance, and a few available MCUs can basically be filtered out.
With a rough direction and a few alternatives, how to further select the most suitable one for your project? You can consider the following factors comprehensively:
Price and Supply, must be considered, after all, no product can afford a delivery time of dozens of weeks;
Lifecycle, should match the product lifecycle;
Upgradability, with the rapid pace of product updates, the chip’s upgradability must be considered;
Technical Support, this point is very important, having good technical support can directly shorten product development time.
At this point, I believe you will have a clearer understanding of your needs and goals, and selecting the right MCU will be much simpler. Now let’s combine specific products and practice: taking the most common wireless earphone charging case as an example, how would you choose a suitable MCU for it?
Sister Ni usually follows this process:
First, analyze its functional requirements: besides charging and discharging management, the system control function of the charging case is also very important, needing to monitor the battery’s working status, detect the closure of the Hall switch, determine whether the lid is open or whether the earphones are placed inside, and also be responsible for enabling other chips in the charging case, as well as personalized charging status display.
Furthermore, determine the resources and requirements of the MCU: the main frequency requirement is not high; needs built-in ADC, UART, I²C; low power consumption.
Based on the above requirements, a chip based on the Arm Cortex-M0+ core can meet them. By comparing the types of MCUs on the market, it can quickly determine the chip, for example, the latest MSPM0 series MCUs from TI can be applied to the charging case.
As a series of MCUs strongly promoted by TI, I believe everyone has seen too many introductions about MSPM0. In the M0+ market, to stand firm, MSPM0 has some unique advantages, here are a few points summarized:
Rich Analog Resources:The analog resources integrated in the MSPM0 chip are the best gift given by TI to the MSPM0. The 12-bit ADC with a maximum speed of 4MSPS supports hardware oversampling to 14 bits, and very few MCUs have internal ADCs that can achieve such high effective bit numbers; high-speed low-power comparators; zero-drift operational amplifiers and transimpedance amplifiers, and the amplifiers have time-multiplexed pin reuse functions, thus replacing more external operational amplifiers. Compared to other MCUs with the same M0 core, these resources are basically absent.
Diverse Product Models:The MSPM0 series was launched with 3 series and over 100 product models, with different pin configurations and flash sizes, and diverse packaging. The three series are: the MSPM0C series, with a main frequency of 24MHz, focusing on low cost and high-performance analog peripheral integration; the MSPM0L series, with a main frequency of 32MHz, focusing on low power consumption and high cost performance; and the MSPM0G series, achieving the highest main frequency of 80MHz in the M0 core, focusing on high performance and high computing speed.
Easy Upgrades:Chips with the same number of pin configurations in the MSPM0 series can be pin-to-pin compatible replacements. For example, if you start using MSPM0L1343 in a project, and later the system upgrades and resources are insufficient, you can directly replace it with MSPM0G1506 with the least cost and easily upgrade.
Widespread Market Applications:With a main frequency ranging from 32MHz to 80MHz, and integrated CAN-FD control, the MSPM0 can easily handle consumer electronics applications as well as industrial or automotive applications.
At the same time, the documentation, source code, and demo examples for MSPM0 are relatively rich, and there are also some Chinese materials and training tutorials to help everyone get started. The development tools for MSPM0 include not only CCS but also support for KEIL, IAR, and SysConfig tools for graphical configuration.
Of course, no matter how good it sounds, personal experience is even more convincing. Based on the MSPM0 chip, we specially designed two projects: the emergency storage station design and the desktop robot.
In the next two weeks, Darwin will launch these two interesting projects on Bilibili, so everyone can pay attention in advance.
Project Sharing | Electrical Competition Series | Artificial Intelligence | Postgraduate Entrance Examination
Must-Know Knowledge Points | Graduation Design | Switch Power Supply | Job Hunting
We are NiMo, the founder of Darwin, who only talks about technology and not flirting. Darwin is an online education platform aimed at serving professionals in the electronics industry, providing skill training videos covering popular topics in various sub-fields such as embedded systems, FPGA, artificial intelligence, etc. It also tailors layered learning content for different groups, such as commonly used knowledge points, disassembly and evaluation, electrical competitions/intelligent vehicles/postgraduate entrance examinations, etc. Welcome to follow.
