Arduino NANO Pinout Diagram

Updated: June 13, 2026

The Arduino Nano is a smaller, breadboard-friendlier version of the Arduino Uno. This Arduino Nano Pinout diagram reference is a handy guide for using this board.

Interactive Arduino Nano Pinout Diagram

Arduino Nano Safe-to-Use Pins

For most beginner projects, the safest general-purpose pins are:

Use Case	Recommended Pins	Avoid / Be Careful
Digital input/output	D2–D9	D0/D1 if using Serial
PWM output	D3, D5, D6, D9, D10, D11	D5/D6 if relying heavily on timing
I2C modules	A4 SDA, A5 SCL	Needs pullups on many modules
SPI modules	D10–D13 or ICSP header	D13 also controls built-in LED
Analog sensors	A0–A5	A6/A7 are analog-input only
External interrupts	D2, D3	D2 has INT0, D3 has INT1

Arduino Nano Pinout Description

The Arduino Nano pins are divided into digital pins, analog pins, power pins, and communication pins. Like the Arduino Uno, the Nano uses the ATmega328P microcontroller, but it includes two extra analog input pins: A6 and A7. Several pins also have alternate functions such as PWM, UART, I2C, SPI, and external interrupts.

Digital Pins

Nano Pin	ATmega328P Port	Functions	Notes
D0	PD0	RX, UART	Used for serial upload/USB communication
D1	PD1	TX, UART	Used for serial upload/USB communication
D2	PD2	INT0	External interrupt
D3	PD3	PWM, INT1	PWM pin
D4	PD4	Digital I/O	General purpose
D5	PD5	PWM	Timer0 PWM
D6	PD6	PWM	Timer0 PWM
D7	PD7	Digital I/O	General purpose
D8	PB0	Digital I/O	General purpose
D9	PB1	PWM	Timer1 PWM
D10	PB2	PWM, SS	SPI chip select
D11	PB3	PWM, MOSI/COPI	SPI data out
D12	PB4	MISO/CIPO	SPI data in
D13	PB5	SCK, LED_BUILTIN	On-board LED

Analog Pins

Nano Pin	ATmega328P Port	Functions	Notes
A0	PC0	ADC0, Digital I/O	Analog input or digital pin
A1	PC1	ADC1, Digital I/O	Analog input or digital pin
A2	PC2	ADC2, Digital I/O	Analog input or digital pin
A3	PC3	ADC3, Digital I/O	Analog input or digital pin
A4	PC4	ADC4, SDA	I2C data pin
A5	PC5	ADC5, SCL	I2C clock pin
A6	ADC6	Analog input only	Cannot be used as digital I/O
A7	ADC7	Analog input only	Cannot be used as digital I/O

 

Power Pins

Pin	Function	Notes
VIN	External input voltage	Typically used with 7–12V input
5V	Regulated 5V	Can power 5V modules if current is within limits
3.3V	3.3V output	Limited current output
GND	Ground	Common reference for circuits
RESET	Reset pin	Pull LOW to reset the board
AREF	Analog reference	Optional external reference for ADC

 

Also, notice that the ATMega pins for each Arduino pin are also provided in the pinout diagram above. For details on how to use these pins, see Arduino Port Manipulation.

Arduino Nano Digital Pins

The Arduino Nano has 14 digital I/O pins labeled D0 to D13. These pins can be used with pinMode(), digitalWrite(), and digitalRead(). They operate at 5V logic.

Arduino Nano PWM Pins

The PWM-capable pins are D3, D5, D6, D9, D10, and D11. These pins can be used with analogWrite() to dim LEDs, control motor speed, or generate simple variable-output signals.

Arduino Nano Analog Pins

The Nano has eight analog input pins: A0 to A7. A0 to A5 can also be used as digital pins, while A6 and A7 are analog-input only.

Arduino Nano Power Pins

The Arduino Nano can be powered through the USB port, the VIN pin, or the 5V pin. For most projects, USB is the safest option during development. The VIN pin is used when supplying an external voltage, while the 5V and 3.3V pins can power small external modules if their current requirements are within the board’s limits.

Arduino Nano I2C Pins

The I2C pins are A4 for SDA and A5 for SCL. These are commonly used with LCD modules, RTC modules, EEPROMs, and sensors like the BME280.

Arduino Nano SPI Pins

The SPI pins are D10, D11, D12, and D13. The same SPI signals are also available on the ICSP header.

Arduino Nano UART Pins

D0 and D1 are the hardware serial pins. Avoid using them for normal I/O when uploading code or using Serial Monitor.

Arduino Nano vs Arduino Uno Pinout

The Arduino Nano and Arduino Uno both use the ATmega328P and share many of the same pin functions. The main differences are the board size, USB connector, power jack, and the extra analog inputs A6 and A7 on the Nano.

Feature	Arduino Nano	Arduino Uno
Microcontroller	ATmega328P	ATmega328P
Digital I/O	14	14
PWM Pins	6	6
Analog Inputs	8	6
USB Connector	Mini-B on classic Nano	USB-B on classic Uno
Breadboard Friendly	Yes	No

 

Common Arduino Nano Pinout Mistakes

Using D0 and D1 for normal I/O

D0 and D1 are connected to the hardware serial interface. If you connect sensors, relays, or modules to these pins, uploading sketches or using the Serial Monitor may fail.

Using A6 and A7 as digital pins

A6 and A7 are analog-input only. Use A0 to A5 if you need analog pins that can also work as digital I/O.

Forgetting that D13 is connected to the built-in LED

D13 can be used as a normal digital pin, but it is also connected to the on-board LED.

Connecting I2C modules to the wrong pins

On the Arduino Nano, SDA is A4 and SCL is A5.

 

Arduino Nano Pinout Code Examples

Blink the Built-in LED on D13

void setup() {
  pinMode(13, OUTPUT);
}

void loop() {
  digitalWrite(13, HIGH);
  delay(500);
  digitalWrite(13, LOW);
  delay(500);
}

Read an Analog Sensor on A0

void setup() {
  Serial.begin(9600);
}

void loop() {
  int sensorValue = analogRead(A0);
  Serial.println(sensorValue);
  delay(500);
}

Generate PWM Output on D9

void setup() {
  pinMode(9, OUTPUT);
}

void loop() {
  analogWrite(9, 128); // about 50% duty cycle
}

 

Arduino NANO Schematic Diagram

The Arduino NANO was originally designed by Gravitech and has been included as one of the official Arduino boards. Here is its schematic diagram:

Arduino Nano Pinout FAQ

What are the PWM pins on Arduino Nano?

The PWM pins are D3, D5, D6, D9, D10, and D11.

What are the I2C pins on Arduino Nano?

A4 is SDA and A5 is SCL.

What are the SPI pins on Arduino Nano?

D10 is SS, D11 is MOSI/COPI, D12 is MISO/CIPO, and D13 is SCK. These signals are also available on the ICSP header.

Can A6 and A7 be used as digital pins?

No. A6 and A7 are analog-input only on the Arduino Nano.

What voltage does the Arduino Nano use?

The Nano uses 5V logic. VIN accepts 7–12V input according to the official Arduino pinout.