Digital I/O & Pins
• 14 digital I/O pins
• 6 pins support PWM output (Pins 3, 5, 6, 9, 10, 11)
• 6 analog input pins (A0–A5)
• 1 external reset pin

Current
• DC Current per I/O pin: 20 mA
• DC Current for 3.3V pin: 50 mA

Memory
• Flash memory: 32 KB
• (0.5 KB used by bootloader)
• SRAM: 2 KB
• EEPROM: 1 KB

Clock Speed
• 16 MHz

Communication
• UART (Serial)
• SPI
• I2C (TWI)

Power
• Can be powered via:
o USB Type-B port
o DC barrel jack
o Vin pin

USB Chip
• ATmega16U2 for USB-to-serial communication (in official boards)

Physical
• Length: 68.6 mm
• Width: 53.4 mm
• Weight: ~25 g