Board pinout
Arduino Nano Pinout
A breadboard-friendly Uno in a tiny footprint. Same ATmega328P and 5V logic, ideal for compact permanent builds. It runs at 5V logic with 20 usable GPIO pins. Every value below is verified against the pin map Banana Board uses to check real designs.
Interfaces
Watch out for
Input-only: A6, A7. These read signals but cannot drive an output and have no internal pull-up.
5V logic: safe with 5V sensors and modules, but level-shift when talking to 3.3V-only parts.
Pins by capability
A quick map of which pins do what. Colours match the pin table below.
Starter circuits to learn with
Beginner projects for the Arduino Nano. The pins below come straight from its real pin map, so they are safe to wire as shown.
Blink an LED
D0Drive an LED (through a ~220Ω resistor) from D0 and toggle it in loop(). The classic first sketch.
digitalWrite()
Fade an LED (PWM)
D3Use D3 with analogWrite() to smoothly ramp an LED from off to full brightness.
analogWrite()
Read a potentiometer
A0Wire a potentiometer's wiper to A0 and read its position with analogRead().
analogRead()
Read a button
D1Connect a push button between D1 and GND, set the pin to INPUT_PULLUP, and skip the external resistor.
digitalRead() + INPUT_PULLUP
Connect an I2C sensor or OLED
A4 / A5Wire SDA to A4 and SCL to A5 (plus power and GND) to talk to parts like a BME280 sensor or an SSD1306 OLED.
Wire.h
Try it without the hardware
Describe one of these circuits in the Studio and the Arduino Nano runs a true in-browser simulation (avr8js): watch your loop() drive the LED or read the input before you touch a breadboard.
Full Arduino Nano pin map
| Pin | GPIO | Capabilities | Voltage | Notes |
|---|---|---|---|---|
| 5V+5V | — | Power | 5V | Regulated 5V out (also USB 5V). |
| 3V33.3V | — | Power | 3.3V | 3.3V from the USB bridge (low current). |
| VIN | — | Power | — | Unregulated input (7-12V). |
| GNDGND2 | — | GND | — | Ground. |
| D00 | 0 | RXDigital | — | Serial RX — avoid if using Serial. |
| D11 | 1 | TXDigital | — | Serial TX — avoid if using Serial. |
| D22 | 2 | Digital | — | — |
| D33 | 3 | DigitalPWM | — | — |
| D44 | 4 | Digital | — | — |
| D55 | 5 | DigitalPWM | — | — |
| D66 | 6 | DigitalPWM | — | — |
| D77 | 7 | Digital | — | — |
| D88 | 8 | Digital | — | — |
| D99 | 9 | DigitalPWM | — | — |
| D1010 | 10 | SSDigitalPWM | — | — |
| D1111 | 11 | MOSIDigitalPWM | — | — |
| D1212 | 12 | MISODigital | — | — |
| D1313 LED_BUILTIN | 13 | SCKDigital | — | Built-in LED. |
| A014 | 14 | DigitalADC | A0 | — |
| A115 | 15 | DigitalADC | A1 | — |
| A216 | 16 | DigitalADC | A2 | — |
| A317 | 17 | DigitalADC | A3 | — |
| A418 | 18 | SDADigitalADC | A4 | — |
| A519 | 19 | SCLDigitalADC | A5 | — |
| A6input-only | — | ADC | A6 | Analog input only — no digital I/O. |
| A7input-only | — | ADC | A7 | Analog input only — no digital I/O. |
26 of 26 pins shown. Data verified against the board pin map Banana Board uses to check every design.
Design an Arduino Nano PCB from a sentence
Describe your Arduino Nano project and Banana Board wires it to these exact pins, validates it, then places and routes a fab-ready 2-layer board.
Frequently asked questions
Is the Arduino Nano 3.3V or 5V logic?
The Arduino Nano runs at 5V logic. Its I/O pins output and tolerate 5V, so it interfaces directly with 5V sensors and modules, but you must level-shift when talking to 3.3V-only parts.
How many GPIO pins does the Arduino Nano have?
The Arduino Nano exposes 20 usable GPIO pins, plus 3 power and 1 ground pins.
Which pins are PWM-capable on the Arduino Nano?
PWM (analogWrite / tone) is available on D3, D5, D6, D9, D10, D11.
How many analog (ADC) inputs does the Arduino Nano have?
The Arduino Nano has 8 ADC-capable pins: A0, A1, A2, A3, A4, A5, A6, A7.
What are the I2C pins (SDA and SCL) on the Arduino Nano?
The default I2C bus uses A4 for SDA and A5 for SCL. Add pull-up resistors (typically 4.7k) if your module does not include them.
What are the SPI pins on the Arduino Nano?
The hardware SPI pins are SCK D13, MOSI D11, MISO D12, and SS D10.
Which pins are the serial (UART) TX and RX on the Arduino Nano?
The default hardware serial uses D1 for TX and D0 for RX.
Which pins on the Arduino Nano are input-only?
A6, A7 are input-only. They can read digital or analog signals but cannot drive an output and have no internal pull-up or pull-down.
Build it, do not just look it up
Describe your circuit in one sentence and Banana Board wires it to these exact pins, validates it, and lays out a fab-ready PCB.