General:

• Microcontroller: ATmega328P
• Operating Voltage: 5V
• Input Voltage (recommended): 7–12V
• Input Voltage (limit): 6–20V
• DC Current per I/O Pin: 20 mA
• DC Current for 3.3V Pin: 50 mA

Memory:

• Flash Memory: 32 KB (ATmega328P) of which 0.5 KB used by bootloader
• SRAM: 2 KB
• EEPROM: 1 KB

Clock Speed:

• 16 MHz (ceramic resonator or crystal oscillator)

I/O:

• Digital I/O Pins: 14 (of which 6 provide PWM output)
• PWM Digital I/O Pins: 6
• Analog Input Pins: 6
• Analog Input Voltage Range: 0–5V

Communication:

• UART (Serial): Yes (via ATmega16U2/CH340G/FT232 depending on version)
• I2C / TWI: Yes (A4 = SDA, A5 = SCL)
• SPI: Yes (Pins 10–13)
• USB: Standard Type-B (for power and programming)

Power:

• Power Jack: Barrel Jack (for external supply 7–12V)
• USB Supply: 5V
• VIN Pin: For external power (7–12V)