Input/output:

There aretotal 14 digital Pins and 8 Analog pins on your Nano board. The digitalpins can be used to interface sensors by using them as input pins or driveloads by using them as output pins. A simple function like pinMode() and digitalWrite() canbe used to control their operation. The operating voltage is 0V and 5V fordigital pins. The analog pins can measure analog voltage from 0V to 5V usingany of the 8 Analog pins using a simple function like analogRead().

These pins apart fromserving their purpose, can also be used for special purposes, which arediscussed below:

·        Serial Pins 0 (Rx) and 1 (Tx): Rx and Txpins are used to receive and transmit TTL serial data. They are connected withthe corresponding ATmega328P USB to TTL serial chip.

·        External Interrupt Pins 2 and 3: These pinscan be configured to trigger an interrupt on a low value, a rising or fallingedge, or a change in value.

·        PWM Pins 3, 5, 6, 9 and 11: These pinsprovide an 8-bit PWM output by using analogWrite() function.

·        SPI Pins 10 (SS), 11 (MOSI), 12 (MISO) and 13(SCK): These pins are used for SPI communication.

·        In-built LED Pin 13: This pin isconnected with a built-in LED. When pin 13 is HIGH – LED is on and when pin 13is LOW, it is off.

·        I2C A4 (SDA) and A5 (SCA): Used for IICcommunication using Wire library.

·        AREF: Used to provide referencevoltage for analog inputs with analogReference() function.

• Reset Pin: Making this pin LOW, resets the microcontroller.

ArduinoNano specifications