What attitude should beginners take to learn single-chip microcomputers, some very improper attitudes must be corrected
Having brought so many students, some people think that 8-bit computers are really too simple. They feel that they have already started to learn and want to learn embedded, play ARM, and get Linux. In the eyes of these people, they can understand microcontroller It does not mean that it can be embedded. Let me correct the views of the "great gods" here. They are actually two different concepts, and ask your heart, does knowing how to use a single-chip microcomputer mean that you can really use a single-chip microcomputer? Without hesitation, it is still far away. Whether it is an 8-bit computer or a 32-bit computer, these are just a tool for us to solve problems. Many people say that they can use the C language, but a few people can really use it. What about Linux and uCOS written in C language?
So for beginners, your attitude is very important, don't float in the air, you need to step on the ground, it doesn't matter which MCU you choose, the important thing is that you need to be proficient and good at one, and the principles of basic general models are similar. , it is a piece of cake to be proficient in one and then use other companies, and then go on to learn 32-bit processors is also easy and comfortable, on the contrary, each microcontroller is always in the entry state for you.
There are many applications of 51 single-chip microcomputer, which is easier for novices to use. Moreover, 51 single-chip microcomputer is the originator. After learning it, it is not a problem to make other models. I will share some basic concepts of 51 single-chip microcomputer serial communication. It usually refers to the The information interaction between the single-chip microcomputer and the computer, or between the single-chip computer and the single-chip computer, is usually the communication between the lower computer and the upper computer. The lower computer generally refers to the single-chip computer, which means to do some simple data collection, or For some controls, or some offline instruments, the upper computer often refers to a PC or a computer, which can communicate with the lower computer for serial data transmission or transmission of some control commands.
Serial communication is usually used when the information exchange between the single-chip microcomputer and the single-chip microcomputer. In addition, when the single-chip microcomputer system is constructed, some peripheral devices, or peripheral chips, or some modules and the single-chip microcomputer are usually used for the interface between the single-chip microcomputer. Serial ports, such as Bluetooth modules, or wireless CP modules, are usually used as serial communication interfaces when interfacing with single-chip microcomputers. Some use 485 interfaces, as well as some instruments and some intelligent sensors. With the standard 485 interface, if you want to do some data interface through 485, the single-chip microcomputer still needs to use serial communication, and the interface chip is used to convert it into a 485 interface.
The serial communication inside the MCU is relatively important. When building a system, or in the process of debugging some programs, the serial port of the MCU is often used as the output window for debugging, and some parameters or parameters in the program debugging process are used. Some data can be transmitted to the computer through the serial port, for example, use the serial port debugging assistant to view some processes of the program's operation, or debug the program to eliminate some problems. Communication makes a simple understanding.
Using the serial communication interface of the single-chip microcomputer to communicate, there are generally two forms of parallel communication and serial communication. In the single-chip system, these two situations are often used at present. Parallel communication refers to the transmission of multiple bits at the same time. For example, if a byte is transmitted at the same time, it will occupy eight bits, the data line needs eight lines, and some control lines are also needed. If 16 bits are transmitted at the same time, 16 lines are needed, and 32 lines are required to transmit. One bit requires 32 lines, so there will be more parallel communication data lines, which will bring more physics, higher hardware costs, and relatively short transmission distances, which are prone to external interference.
Parallel communication will not be introduced too much. Now, serial communication is often used, including computer systems. The USB interface is the serial communication interface. The parallel interface in the past is rarely used now, including the internal computer. , In the past, when the old computer opened the main box, you will find that there are many cables inside, which are cables connected together with flat cables. There will be a lot of cables, dozens of them. After opening the current main box, you will find that the inside of the main box of the computer is very simple, only a few cables are relatively simple, all of which use the serial interface and are no longer used. Parallel communication interface.
Serial communication can only be transmitted bit by bit at the same time. A byte of data needs to be divided into bits and transmitted bit by bit. It needs a data line to transmit data. Parallel communication requires more Only the root data line can transmit data. It is the same as the eight-lane and single-lane. Eight-lane can transmit eight vehicles at the same time, and the single-lane can only pass one vehicle at the same time. The speed is relatively fast, and its speed can meet the requirements of the application system. Now the technical level of serial communication is developing rapidly, and serial communication is used in many occasions, and its speed can reach very high, such as the current Mobile hard drives no longer use the parallel interface, but use the serial interface of USB. Learn about the difference between parallel communication and serial communication.
The standard of serial communication is mainly divided into three types, simplex, half-duplex and full-duplex. The serial communication of 51 single-chip microcomputer is full-duplex. In fact, the communication standard is mainly whether the transmission flow of data is one-way or two-way. Yes, simplex is one-way, such as a broadcast speaker. The broadcaster transmits the information that needs to be broadcast, and the receiver can only receive the information. In the 80s, the BB machine can only receive information. After displaying the information, you need to The person who wants to communicate with the sender has to call back, which means that they are actually a simplex system, and later there is a half-duplex method, which means that both the sender and the receiver can send and receive. data, but not at the same time, that is to say, the A side also wants to send the data to the B side, or the B side wants to send the data to the A side. The same is true for the B side. This is the case with walkie-talkies. You cannot listen when you are talking, and you cannot speak when you are listening. This is half-duplex. Sending and receiving cannot be performed at the same time. 485 communication basically uses a standard of half-duplex.
If you are interested in single-chip microcomputer, you can check the content shared in previous issues . I hope it can help you to take some detours on the road of learning single-chip microcomputer . If you want to get started with single-chip microcomputer, you can continue to pay attention to Chuangwei single-chip microcomputer programming . Reply "Take me to learn" to see more content sharing .
