Basic knowledge of serial communication

    Serial communication is a common data transmission method used to exchange data between computer systems, embedded systems and external devices. The following are the basics of serial communication:

    Serial interface: Serial communication uses serial interfaces to transmit data, that is, data bits are sent or received one after another in sequence, and serial interfaces require only a small number of lines compared to parallel interfaces (which transmit multiple bits at the same time).

    Common serial ports: Common serial ports include RS-232, RS-485, and UART. RS-232 is a standardized serial communication protocol commonly used to connect computers to external devices such as modems and printers. RS-485 is a multi-point communication protocol that enables data transmission between multiple devices.

    Communication parameters: Important parameters in serial communication include the Baud rate, data bit, check bit, and stop bit. Baud rate indicates the number of bits transmitted per second, data bits indicate the number of bits per data byte, check bits are used to detect errors during data transmission, and stop bits indicate the end of data byte transmission.

    Data transmission mode: Serial communication can adopt synchronous transmission or asynchronous transmission mode. Synchronous transmission requires the clock signals of the sender and receiver to be synchronized, while asynchronous transmission determines the start and end of the data frame by the start and stop bits.

    Software control: Serial communication requires software to control the sending and receiving of data. On a computer, serial programming interfaces (such as Windows apis or Linux serial device files) can be used for configuration and data manipulation of serial communication.

    Data format: Data in serial communication can be characters, binary data, or other formats. Before sending and receiving data, the format of the data needs to be agreed to ensure proper parsing and processing.

    Error detection and correction: In order to ensure the reliability of data transmission, check bits are often used in serial communication for error detection and correction. Common check methods include parity check and cyclic redundancy check (CRC).

    Serial communication is widely used in many fields, such as serial device control, sensor data acquisition, embedded system communication and so on. Understanding the basic knowledge of serial communication is very important for connecting, configuring, and exchanging data with serial devices.