Design of single chip microcomputer multi machine communication system

Hardware--- 8051 microcontroller.

The workload is too much, and my graduation project is to use a single-chip microcomputer to control lighting.

It's going to be months, big brother.

It's too lazy to lean upstairs, right?When people ask about the system design, you can talk about RS485, and you can't give points.

It's very simple, just find a book on microcontrollers and you can solve it.

It's too much work......Ask for a share and give money by the way.

MCU multi-machine communication, a host multiple slaves + a communication protocol can be, the normal serial port setting can be, the protocol can be in the form of data packets, such as: boot character, slave number, data length, instruction type, data 1 --- data n, check code, end character, to the host to send instructions slave answer, slave machine needs to be assisted by the host.

Lin Daiyu and Jia BaoyuLin Daiyu and Jia Baoyu.

The simplest communication method between MCU and PC is to use serial port, and a pair of serial port lines in the RS232 port of PC correspond to a pair of serial port pins of MCU for communication.

The most important parameters of serial communication are baud rate, data bits, stop bits and parity, and data is transmitted in bits.

What format is used for the communication data between the microcontroller and the PC needs to be defined first, and then written in the program. For example, if the communication is ASCII code string, the microcontroller receives the data from the PC and stores the data in the char format. If the decimal number is being communicated, the data is stored in a variable in int format.

The same will be done with programs on PCs.

There are too many programs on the Internet about serial communication between single-chip microcomputers and PCs, and it is recommended that you understand them, and you should be very clear after reading them.

The single-chip microcomputer is a very basic communication equipment, it is not like the PC, switch, router, which has a complete set of communication protocols, the communication protocol of the single-chip microcomputer is defined by the designer, of course, some advanced single-chip microcomputers have communication modules, but in the final analysis, there is still a designer to burn the program into it first. Further, in fact, the communication modules of those switches and routers are actually chips like single-chip microcomputers.

It is impossible for a microcontroller to receive characters without an operating system (e.g. Linux).

For single-chip microcomputer transmission, if you want to send a number to the PC, for example, send the number '1' to the PC, and let the serial port debugging software display it in the form of ASCII characters, you have to send it'1'ASCII code 31

In fact, all the hexadecimal data received by the debugging assistant is the result of ASCII conversion of the hexadecimal data received by the debugging assistant, whether the ASC character display or HEX display.

If the hexadecimal system is displayed, then the debugging assistant shows the actual data received.

If the ASC is displayed, then the debugging assistant will check the received HEX data in the ASCII table to see which character the hexadecimal data represents.

If you want the microcontroller to be able to handle characters as well, like you said'/n', then you need to store an ASCII table in the microcontroller, and then use the received characters to look up the table, and then convert.

It's still yours'/n'For example, the microcontroller receives 0a, and then goes to the ASCII table difference, and 0a represents the formal n

It is recommended that you read the books on the subject.

The serial port communication of single-chip microcomputer is to transmit one byte at a time, that is, 8-bit binary digits.

That's the most basic knowledge.

The landlord wants to transmit: , or anything else, just treat them as 8-bit binary numbers.

This is also the simplest knowledge. Simple, nothing could be simpler.

There is just a communication format that needs to be set up.

Not at all: ASCII codes, protocols, packets, frames, garbled characters.

He is right, and I adore him! Learning from him, I also threw bricks and stones.

The following is a simple single-chip microcomputer and PC to accept the sending of information program I wrote before, you can refer to it, the network topology I use is star-shaped, the program begins to have the function of confirming the address sent by the PC, and then does not stop accepting the agreed data length, and the accepted data is stored in the storage space from 80h, these you can change according to your own requirements, but the PC side must send the address first, after the single-chip microcomputer sends the address confirmation, you can send data.

include Crystal oscillator.

#include

define data51 dbyte[0x80] 80h storage data.

define addressid 1 native address.

unsigned char call,*p;The call command 00h (received by the slave) 01h (sent by the slave).

unsigned char l;The number of words sent.

void rs485();

main()

void rs485()

void counter4(void) interrupt 4 serial port interrupt.