Digital power modules utilize various communication protocols such as I2C, SPI, CAN, and UART, as well as interaction protocols based on these, such as CANopen, SAE 1939, SMbus, PMbus, and Modbus.This article simulates a Q&A regarding knowledge related to UART communication.
Question 1: What are the characteristics of UART communication?
Answer: Asynchronous communication, low cost, widely used.
(This assesses the understanding of several significant characteristics of UART communication; others such as point-to-point, weak data verification, and the absence of a clock line can also be discussed. The above answer can be elaborated upon.)
Question 2: What is the relationship between RS485, RS232, and UART?
Answer: UART is a logical layer protocol that defines the format of the data and the method of transmission and reception, but does not specify the electrical characteristics. RS232 and RS485 are physical layer standards that define signal levels, cable types, communication distances, etc.
(This assesses the understanding of these concepts in real projects and whether there are misconceptions, as hardware and on-site construction generally use the term RS485, while coding involves UART. Clarifying this helps others locate issues. Differences between RS485 and RS232 can also be discussed.)
Question 3: Can data received from the UART port by a microcontroller be used directly?
Answer: No, because the UART protocol only has parity checking, which is too weak for data verification. In the presence of interference, erroneous data may be received, so a strong verification method such as CRC16 should be added at the application layer to ensure reliability.
(This assesses whether UART has been used in projects. Of course, for displaying data to humans, it can be used, such as for data printing ports, since humans have a certain ability to discern data validity. However, parameters input from external sources to the microcontroller cannot be used directly.)
Question 4: Have you used the Modbus protocol? Please provide a brief introduction.
Answer: Modbus is a protocol framework that operates on a master-slave architecture. Its logical protocol can be based on UART or TCP/IP, and the physical layer can be not only RS485 but also Ethernet.
(This primarily assesses whether Modbus has been used in projects and the understanding of concepts such as Modbus RTU and TCP.)
The images in this article are sourced from YouTube @Foolish Engineer Basics of UART Communication | UART Frame Structure
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