A brief description of the working principle of microcontroller iic communication

Microcontroller IIC communication refers to data transmission and communication through the IIC bus under the control of the microcontroller. IIC communication is a serial communication method that transmits data through two lines, SCL and SDA. The SCL line is a clock line and the SDA line is a data line. The IIC communication protocol adopts master-slave communication. The master device sends a request, the slave device responds to the request, the slave device returns data, and the master device receives the data. The roles of the master and slave devices can be interchanged during the communication process.

IIC communication is divided into two modes: transmission mode and register access mode. The transmission mode refers to the transmission of data, and the register access mode refers to reading and writing the device's register. In the transmission mode, the master device sends a start signal. After the slave device receives the start signal, it starts waiting for the reception of data. When the master device sends data, the slave device receives the data bit by bit. After receiving the data, the slave device sends a response signal. After receiving the response signal, the master device continues to send data until all data is sent, and then sends a stop signal to end the communication. In the register access mode, the master device first sends the device address and register address. After receiving the address, the slave device starts waiting for the read and write operations of data. When the master device sends data, the slave device receives the data bit by bit. After receiving the data, the slave device sends a response signal. After receiving the response signal, the master device continues to send data until all data is sent, and then sends a stop signal to end the communication.

There are two important concepts in IIC communication: clock frequency and data transmission rate. The clock frequency refers to the frequency of the IIC bus clock signal, generally 100kHz or 400kHz. The higher the clock frequency, the faster the transmission speed. The data transmission rate refers to the speed of data transmission, which is determined by the clock frequency and the number of data bits. The higher the data transmission rate, the faster the transmission speed.

The main application areas of IIC communication are in embedded systems, such as sensors, LCD displays, EEPROMs, real-time clocks, thermometers, etc. IIC communication has the following advantages:

1. Simple and convenient: only two lines are needed to complete data transmission, and the control is simple and convenient.

2. Fast transmission speed: The IIC bus clock frequency is high and the data transmission speed is fast.

3. High reliability: IIC communication adopts master-slave communication, the controller strictly controls the communication process, and the data transmission during the communication process is reliable.

4. Multi-device sharing: The IIC bus adopts a multi-master and multi-slave structure, and multiple devices can use the IIC bus to communicate at the same time.

In short, IIC communication is a communication method widely used in embedded systems. It has the advantages of simplicity and convenience, fast transmission speed, high reliability, and multi-device sharing, etc., which provides convenience for the development and application of embedded systems.