ARDUINO UNO R3 (CH340G) 

Arduino Uno R3 is a widely used microcontroller development board designed for learning electronics, programming, and creating DIY projects. It is based on the ATmega328P microcontroller and uses the CH340G USB-to-Serial converter to enable communication between the board and a computer. Due to its simplicity, reliability, and strong community support, it is one of the most popular Arduino boards worldwide.

Overview:
The Arduino Uno R3 is commonly used in education, robotics, Internet of Things (IoT), automation, and prototyping applications. It allows users to read data from sensors, process that data using programmed logic, and control output devices such as LEDs, motors, relays, and displays. The board is suitable for beginners as well as advanced users who need a stable and versatile development platform.

Main Components:

ATmega328P Microcontroller:
This is the core processing unit of the board and acts as the brain of the Arduino Uno R3. It executes the uploaded program (called a sketch) and manages all operations. It reads input signals from sensors or switches, processes the data, and controls output devices such as LEDs, motors, and modules according to the programmed logic.

CH340G USB-to-Serial Converter:
The CH340G chip enables USB communication between the Arduino board and a computer. It replaces the original ATmega16U2 chip used in official Arduino boards. This chip allows easy uploading of programs and serial communication through a USB cable. On some operating systems, a CH340 driver may need to be installed before use.

Key Features:

Microcontroller Specifications:
Powered by the ATmega328P microcontroller operating at a clock speed of 16 MHz, the board offers stable performance for most embedded applications. It includes 32 KB of flash memory for storing programs, with 0.5 KB reserved for the bootloader. It also provides 2 KB of SRAM for variables and 1 KB of EEPROM for storing data that needs to be retained even after power is removed.

Power Supply:
The Arduino Uno R3 operates at 5V and can be powered through a USB cable or an external power source. The recommended input voltage range is 7–12V, while the absolute limit is 6–20V. This flexibility allows it to be powered using adapters, batteries, or power modules. Boards using the CH340G chip are commonly found in low-cost Arduino versions.

Input and Output Pins:
The board features 14 digital input/output pins that can be used to read digital signals or control digital devices. Out of these, 6 pins support PWM (Pulse Width Modulation) for controlling motor speed, LED brightness, and similar applications. It also includes 6 analog input pins (A0–A5) for reading analog sensor values. Each I/O pin can typically supply up to 20 mA of current.

Communication Interfaces:
Arduino Uno R3 supports multiple communication protocols. UART serial communication is available through pins 0 and 1. SPI communication uses pins 10, 11, 12, and 13, making it suitable for displays, memory cards, and sensors. I2C communication is supported through pins A4 (SDA) and A5 (SCL), allowing connection to multiple devices using only two wires.

Programming:
The board is programmed using the Arduino IDE, which is beginner-friendly and widely supported. It uses a simplified version of C/C++ known as the Arduino programming language. Programs can be uploaded easily via USB, making development fast and efficient.

Applications:
Arduino Uno R3 is used in a wide range of projects including LED control and sensor-based systems, line follower and obstacle-avoiding robots, home automation systems, IoT prototypes, and educational experiments. Its versatility makes it an ideal choice for students, hobbyists, and engineers working on embedded system projects.