1. 통신

 UART:

     - UART vs I2C vs SPI – Communication Protocols and Uses
     - BASICS OF UART COMMUNICATION

 RS232:

     - RS-232 vs. TTL Serial Communication
     - What is RS232 and What is it Used for? - YouTube
     - Explaining The Basics Of RS-232 Serial Communications - YouTube
     - What is RS485 and How it's used in Industrial Control Systems? - YouTube

 I2C:

     - BASICS OF THE I2C COMMUNICATION PROTOCOL
     - I2C
     - Serial communication - I2C

 SPI:

     - BASICS OF THE SPI COMMUNICATION PROTOCOL
     - Serial Peripheral Interface
     - What is SPI? Basics for beginners! - YouTube
     - PROTOCOLS: UART - I2C - SPI - Serial communications - YouTube

 1 Wire:

     - 1-Wire® Technology Overview - YouTube
     - GUIDE TO 1-WIRE COMMUNICATION
     - 1-Wire

2. 센서:

     - Different Types of Sensors and their Applications
     - How Rain Sensor Works and Interface it with Arduino
     - 드론 하늘을 어떻게 ...
     - Interfacing PIC16F877A with NEO-6M GPS module
     - PIC Projects with CCS C compiler
     - What is Hall Effect and How Hall Effect Sensors Work

3. Circuit:

     - Electronic Circuit Diagram

4. 기계장치:

     - How To Mechatronics - YouTube