Bluetooth module interfaces

Jacktang

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If you want to master Bluetooth hardware engineers, you are not a qualified hardware engineer if you don't understand the various interfaces on the Bluetooth module. Do you have a thorough understanding of the communication interface on the Bluetooth module? Many people will be dizzy when they hear about UART interface, IIC interface, SPI interface, etc. Today, let's briefly outline some common interfaces and their differences. In fact, there are generally two ways to wire data transmission: one is a parallel interface and the other is a serial interface. What is a parallel interface? It is what we usually call a parallel port, which is an interface that transmits data in parallel. The so-called "parallel" means that data is transmitted through parallel lines, so that the data transmission speed is greatly improved, but the length of the parallel transmission line is limited. Because the length increases, the interference will increase, and the data will be prone to errors. What is a serial interface? It is what we often call a serial port, which refers to the transmission of data one bit at a time in sequence on a limited number of IOs. There are many such types, generally including: UART, IIC, SPI, CAN, USB, etc. As long as it is a serial transmission interface, it is a type of serial port. It is worth mentioning here that since people used to call the UART port a serial port in the early days, when people talk about serial ports, they generally refer to the UART interface. What are the advantages and disadvantages of parallel interface and serial interface? 1. Serial interface Advantages: Fewer data lines are used, which can save communication costs in long-distance communication. Disadvantages: Because only one bit of data can be transmitted each time, the transmission speed is relatively low. 2. Parallel interface Advantages: Because multiple bits of data can be transmitted together, the transmission speed is very fast. Disadvantages: The number of data lines required depends on the number of bits of memory, so a large number of data lines are required, which is very costly. The differences among USART, SPI and IIC UART interface: UART (Universal Asynchronous Receiver/Transmitter) serial interface is the most commonly used communication technology for microcontrollers and is usually used for communication between microcontrollers and computers and between microcontrollers. SPI interface: SPI (Serial Peripheral Interface) is a serial peripheral interface. SPI is a synchronous serial data transmission standard and a high-speed, full-duplex, synchronous communication bus. It is widely used in many devices. IIC interface: IIC (Inter-Integrated Circuit, integrated circuit bus), also known as I2C, is a two-wire serial bus structure used to connect microcontrollers and their peripheral devices.The main advantages of IIC bus are simplicity and effectiveness. Difference 1. UART is two lines, one for sending and one for receiving, which can communicate in full duplex mode and has relatively few lines. Data is transmitted asynchronously, and the timing requirements for both parties are relatively strict, and the communication speed is not very fast. It is most used in multi-machine communication. Difference 2. Compared with the above UART, the SPI interface has an additional synchronous clock line. The disadvantage of the above UART is also its advantage. The timing requirements for both parties of communication are not strict, and different devices can be easily combined, and the communication speed is very fast. It is generally used in high-speed data communication between internal components of the product, such as large-capacity storage. Difference 3. IIC interface is also a two-wire interface. It transmits data between two wires through complex logical relationships. The communication speed is not high and the program is relatively complicated to write. Generally, it is mainly used to connect with small memories such as 24C02 in single-chip microcomputer systems. Note: SPI and UART can achieve full-duplex, but I2C cannot; I2C is slower than SPI, and the protocol is more complicated than SPI, but the connection is also less than the standard SPI.

yanbao

Thanks for sharing!

alan000345

Good sharing, must support it.