AVR ATmega328

1. Definition

The ATmega328 is an 8-bit AVR microcontroller from Microchip (formerly Atmel).
It is widely used in Arduino Uno boards and other DIY electronics projects.
Known for being beginner-friendly, it balances performance, ease of programming, and affordability.

ATmega328 microcontroller

2. Features

  • Architecture: 8-bit AVR RISC
  • Clock Speed: Up to 20 MHz
  • Flash Memory: 32 KB (with 0.5 KB reserved for bootloader)
  • SRAM: 2 KB
  • EEPROM: 1 KB
  • I/O Pins: 23 general-purpose pins
  • Timers: 3 (two 8-bit, one 16-bit)
  • ADC: 10-bit, up to 6 channels
  • Communication: UART, SPI, I²C (TWI)
  • Operating Voltage: 1.8V – 5.5V
  • Packages: Available in DIP-28, TQFP, QFN

3. Pinout (DIP-28 Package)

  • Digital I/O: 14 pins (D0–D13, some with PWM support)
  • Analog Inputs: 6 pins (A0–A5)
  • Power Pins: VCC, AVCC, GND, AREF
  • Reset Pin: External reset option

4. Common Uses

  • Arduino Uno and Nano boards
  • Robotics and automation projects
  • IoT devices (when combined with WiFi modules like ESP8266/ESP32)
  • Sensor interfacing and control systems
  • Educational electronics kits

5. Advantages

  • Popular and well-documented
  • Supported by Arduino IDE and other toolchains
  • Large community and open-source libraries available
  • Low power consumption in sleep modes
  • Cheap and easy to source

6. Limitations

  • Limited memory compared to modern microcontrollers
  • Slower than 32-bit ARM/ESP chips
  • No built-in WiFi or Bluetooth
  • Limited ADC resolution (10-bit)

7. Example Applications

  • Blinking LED (Hello World of electronics)
  • Reading analog sensor values
  • Driving motors with PWM
  • Serial communication with PCs or other devices
  • DIY weather stations, clocks, and small robots

8. Video Explanation

Video coming soon