Application of communication between PC and single chip microcomputer

This article is about the application of the communication experiment between computers and single-chip microcomputers. It mainly includes the explanation of the experimental principle, hardware circuit diagram, source program, etc.

Contents:

1. Application of MCU serial communication

2. PC controls the MCU IO port output

3. Single chip microcomputer control training guidance and comprehensive application examples

4. The microcontroller sends data to the computer:

[Experimental tasks]

The application of microcontroller serial port communication, through the serial port, our personal computer and microcontroller system communicate.

The personal computer acts as the host computer and sends hexadecimal or ASCII codes to the microcontroller system.

After receiving the data, the system uses LED to display the received data and sends the original data back to the host computer.

[Hardware Circuit Diagram]

[Experimental principle]

RS-232 is a serial bus standard officially announced by the American Electronics Industries Association. It is also the most commonly used serial interface standard. It is used to realize data communication between computers and between computers and peripherals.

The RS-232 serial interface bus is suitable for: the communication distance between devices is no more than 15m, and the maximum transmission rate is 20kBps. The RS-232 protocol uses -5V-15V to represent logic 1; +5V-15V to represent logic 0. We use the MAX232 chip to convert the RS232 level to the TTL level. A complete RS-232 interface has 22 wires and uses a standard 25-pin plug socket. We use a simplified 9-pin plug socket here.

Note that the crystal oscillator we use here is 11.0592M, not 12M, because the baud rate setting requires 11.0592M.