CircuitMix Tools β€Ί Arduino Nano Pinout Reference
Arduino Nano Pinout Reference
A compact, mobile-friendly Arduino Nano pinout reference for makers β€” including digital pins, PWM, analog inputs, I2C, SPI, UART, power pins and ICSP header notes.
πŸ”Œ Key Note: Classic Arduino Nano boards use 5 V logic. The 3.3 V pin is a small auxiliary supply, and A6/A7 are analog-input only.
🧭 Visual Arduino Nano pinout diagram
Arduino Nano Pinout Classic Nano / ATmega328P style board Β· USB connector at top USB MINI ATmega328P Arduino Nano RESET ICSP SPI header D13 SCK / LED 3V3 3.3V Out AREF Analog ref A0 ADC0 A1 ADC1 A2 ADC2 A3 ADC3 A4 SDA / ADC4 A5 SCL / ADC5 A6 ADC only A7 ADC only 5V 5V pin RST Reset GND Ground VIN Input power D12 MISO D11 PWM / MOSI D10 PWM / SS D9 PWM D8 Digital D7 Digital D6 PWM D5 PWM D4 Digital D3 PWM / INT1 D2 INT0 GND Ground RST Reset D0 RX / UART D1 TX / UART POWER GND DIGITAL ANALOG PWM I2C SPI UART
πŸ“Œ Arduino Nano pin quick list
D0RX / UARTSerial receive
D1TX / UARTSerial transmit
D2INT0External interrupt
D3PWM / INT1PWM + interrupt
D4DigitalGeneral purpose
D5PWMPWM output
D6PWMPWM output
D7DigitalGeneral purpose
D8DigitalGeneral purpose
D9PWMPWM output
D10PWM / SSSPI SS + PWM
D11PWM / MOSISPI MOSI + PWM
D12MISOSPI MISO
D13SCK / LEDSPI clock / onboard LED
A0ADC0Analog input
A1ADC1Analog input
A2ADC2Analog input
A3ADC3Analog input
A4SDA / ADC4I2C data
A5SCL / ADC5I2C clock
A6ADC onlyAnalog input only
A7ADC onlyAnalog input only
5V5VLogic supply pin
3V33.3VAuxiliary output
VINInputExternal input
GNDGroundGround pins
AREFAnalog refADC reference
RSTResetReset pin
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PinName / FunctionGroupImportant Notes
D0RX / UART receiveUARTUsed for USB serial. Avoid if Serial Monitor is active.
D1TX / UART transmitUARTUsed for USB serial. Avoid if uploading/debugging.
D2Digital I/O, INT0DIGITALExternal interrupt capable.
D3PWM, INT1PWMPWM output and external interrupt.
D4Digital I/ODIGITALGeneral purpose digital pin.
D5PWMPWMPWM output.
D6PWMPWMPWM output.
D7Digital I/ODIGITALGeneral purpose digital pin.
D8Digital I/ODIGITALGeneral purpose digital pin.
D9PWMPWMPWM output.
D10PWM / SPI SSSPISPI slave select and PWM output.
D11PWM / SPI MOSISPISPI MOSI and PWM output.
D12SPI MISOSPISPI master-in slave-out.
D13SPI SCK / LEDSPISPI clock and onboard LED pin.
A0Analog input ADC0ANALOGCan also be digital pin D14.
A1Analog input ADC1ANALOGCan also be digital pin D15.
A2Analog input ADC2ANALOGCan also be digital pin D16.
A3Analog input ADC3ANALOGCan also be digital pin D17.
A4SDA / ADC4I2CI2C data pin. Also analog input.
A5SCL / ADC5I2CI2C clock pin. Also analog input.
A6Analog input onlyANALOGAnalog input only; not digital I/O.
A7Analog input onlyANALOGAnalog input only; not digital I/O.
5V5 V supplyPOWER5 V logic rail. Current depends on power source/regulator.
3V33.3 V outputPOWERSmall auxiliary 3.3 V supply for low-current modules.
VINExternal inputPOWERInput to onboard regulator. Commonly used with 7–12 V supply.
GNDGroundGROUNDCommon ground reference.
AREFAnalog referencePOWERReference for ADC measurements.
RSTResetPOWERPull low to reset the board.
ICSPMISO, 5V, SCK, MOSI, RST, GNDSPI6-pin programming/SPI header.

πŸ“‹ Common Arduino Nano Interfaces

πŸ” I2C
SDAA4
SCLA5
🟣 SPI
MOSID11
MISOD12
SCKD13
SSD10
〰️ PWM
PWM pinsD3 D5 D6
More PWMD9 D10 D11

πŸ“š Engineering Notes

Uno-compatible pin mapping The classic Nano uses the same ATmega328P pin logic as Arduino Uno, but in a compact breadboard-friendly layout.
A6 and A7 are special A6 and A7 are analog-input-only. Do not use them for digital output, button input, I2C or PWM.
Use common ground Sensors, modules, external power supplies and the Nano must share GND for signals to work correctly.
Serial pins affect uploading D0 and D1 are connected to the USB serial interface. Connected modules can interfere with uploads or Serial Monitor.

Arduino Nano Pinout Reference

This Arduino Nano pinout reference helps makers quickly find digital pins, PWM pins, analog inputs, I2C, SPI, UART and power pins while wiring sensors, displays, relay modules, motor drivers and breadboard circuits.

Arduino Nano vs Arduino Uno pinout

The classic Arduino Nano uses the same ATmega328P family and many of the same pin functions as the Arduino Uno, but the Nano arranges the pins in two compact rows for breadboard use. The main practical differences are the compact board shape and the extra analog-only A6/A7 pins.

❓ Frequently Asked Questions

PWM is available on D3, D5, D6, D9, D10 and D11 on the classic Arduino Nano.
Arduino Nano I2C uses A4 as SDA and A5 as SCL.
SPI uses D10 as SS, D11 as MOSI, D12 as MISO and D13 as SCK. The ICSP header also exposes SPI signals.
No. A6 and A7 are analog-input-only pins on the classic Nano.
Classic Arduino Nano boards normally use 5 V logic. Check your exact board if using a 3.3 V variant or clone.
Yes, VIN feeds the onboard regulator. A common practical range is around 7–12 V, but regulator heating increases with higher voltage and load current.
D0 and D1 are hardware UART pins connected to USB serial. External modules on these pins can interfere with uploading sketches and serial debugging.
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