Advanced Techniques in Communication Protocol Transmission Principles

UART, SPI, I2C and other serial communications are very common methods in embedded development. The underlying communication principles are not difficult, but many beginners struggle to learn them.

Today, I will share some common underlying data transmission principles of communication.

1UART Serial Port

UART: Universal Asynchronous Receiver/Transmitter.

The UART serial port is the most common type of serial communication. Below is an animation showing the connection of the serial port to a host computer and the application of RS232.

2SPI Serial Communication

SPI: Serial Peripheral Interface.

SPI is a common synchronous serial communication protocol, widely used in various applications.

Below is the timing diagram for SPI data transmission:

3I²C Communication

I²C: Inter-Integrated Circuit, literally meaning between integrated circuits, is the abbreviation for I²C Bus.

I²C mainly distinguishes and identifies slave devices through addresses, and its communication principle is relatively simple.

4Infrared Remote Control

Infrared remote controls are quite common in our daily lives; most household remote controls use infrared.

Infrared remote control communicates by controlling pulse width (the duration of high and low levels), establishing a communication link through infrared wireless signals (it does not work if obstructed, but can reflect).

5Serial to Parallel Conversion Circuit

Serial to parallel conversion is the process of converting serial data into parallel data, where the clock controls the transmission of serial data bit by bit, and when it accumulates to a whole (8 bits), it becomes parallel data.

There are many ready-made chips for this converter, and the principle is very simple.

6Others

Here are some other principles of serial transmission (waveforms):