Each of the 14 digital pins on the Arduino Uno can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive ...

Both the Arduino Nano and Uno can be powered via their integrated USB connectors. This automatically supplies regulated 5V power to the board, allowing you to use any USB-supported power source ...

The Metro 328 has been created to provide extra features on top of what you would expect from the Arduino Uno offering plenty of GPIO, Analog inputs, hardware UART SPI and I2C, timers and PWM.