Arduino Nano Pinout

Arduino Nano is a miniature Uno: the same ATmega328P at 16 MHz, but measuring 45 × 18 mm, so it fits on a breadboard. It also has two extra analog inputs, A6 and A7.

Clones with a CH340 converter cost a couple of euros.

Specifications

ATmega328P: 8-bit AVR, 16 MHz
32 kB flash, 2 kB SRAM, 1 kB EEPROM
14 digital pins (6× PWM), 8 analog inputs (A6 and A7 analog only)
UART, I2C (A4/A5) and SPI (D10–D13 and the ICSP header)
5 V logic, 7–12 V power input (VIN) or mini USB power
FT232RL converter (original) or CH340 (clones)
45 × 18 mm

Clones often ship with the older bootloader – if uploading from the Arduino IDE fails, try the ATmega328P (Old Bootloader) processor option. The Nano Every, Nano 33 and Nano ESP32 share the same dimensions and pin layout, but use different chips.

Pinout and pin table

Hover over a pin in the diagram or a table row; use the filter to highlight a bus. You can download the pinout as PNG or SVG.

Pin names:

Download:PNG SVG

License: CC BY 4.0 · How to credit

Pin table – Arduino Nano
Pin	Name	Chip port	Direction	UART	I2C	SPI	PWM	ADC	Note
1	D1	PD1	input/output	TX					UART TX – shared with the USB-serial converter
2	D0	PD0	input/output	RX					UART RX – shared with the USB-serial converter (program upload)
3	RST		input						Reset – connecting to GND restarts the chip
4	GND		–
5	D2	PD2	input/output						External interrupt INT0
6	D3	PD3	input/output				PWM		External interrupt INT1; PWM from Timer 2 (OC2B)
7	D4	PD4	input/output
8	D5	PD5	input/output				PWM		PWM from timer 0 (OC0B)
9	D6	PD6	input/output				PWM		PWM from timer 0 (OC0A)
10	D7	PD7	input/output
11	D8	PB0	input/output
12	D9	PB1	input/output				PWM		PWM from timer 1 (OC1A)
13	D10	PB2	input/output			SS	PWM		PWM from timer 1 (OC1B); SPI SS
14	D11	PB3	input/output			MOSI	PWM		PWM from timer 2 (OC2A); SPI MOSI
15	D12	PB4	input/output			MISO			SPI MISO
16	D13	PB5	input/output			SCK			SPI SCK; onboard LED "L"
17	3V3		output						3.3 V output for light loads only – on the original from the FT232RL converter (max. 50 mA), even less on CH340 clones.
18	AREF		input						ADC reference (default is 5 V)
19	A0	PC0	input/output					ADC0
20	A1	PC1	input/output					ADC1
21	A2	PC2	input/output					ADC2
22	A3	PC3	input/output					ADC3
23	A4	PC4	input/output		SDA			ADC4	I2C SDA (Wire)
24	A5	PC5	input/output		SCL			ADC5	I2C SCL (Wire)
25	A6		input					ADC6	Analog input only – cannot be used as a digital pin
26	A7		input					ADC7	Analog input only – cannot be used as a digital pin
27	5V		input/output						5 V from the regulator or from USB, or 5 V input
28	RST		input						Reset – connecting to GND restarts the chip
29	GND		–
30	VIN		input						Power input 7–12 V (5 V regulator)

What to watch out for

D0 and D1 (UART) share the USB-serial converter – connected peripherals interfere with uploading.
A6 and A7 are analog only – pinMode() and digitalRead() don’t work on them.
The 3V3 pin is for light loads only.
Draw at most 20 mA per pin and no more than 200 mA from the whole chip.

Arduino Nano projects on chiptron.eu/

Projects and guides on chiptron.eu/:

GPS logger with Arduino Nano – logs position to a microSD card, programmed in Visuino
Power Shield for Arduino – controls power devices from an Arduino Nano, Uno or Mega
Wokwi – an online simulator for Arduino Nano, Uno and ESP32 right in the browser