Arduino Nano

Interactive Arduino Nano pinout with PWM, I2C, SPI and the analog-only A6/A7 marked, old-bootloader upload fix, and a compile-checked blink.

5 V logic

Community draft — report a mistake

MCUATmega328P, 16 MHz, 8-bit AVR

Flash / SRAM32 KB (bootloader included) / 2 KB

EEPROM1 KB

I/O14 digital (6 PWM), 8 analog in (A6/A7 analog only)

USBMini-USB; CH340 on most clones, FT232 on originals

Typical price₹250–400 (clone, indicative)

The Nano is the Uno shrunk onto a 30-pin stick that plugs straight into a breadboard. Same ATmega328P, same 16 MHz, same libraries — plus two extra analog inputs, A6 and A7, which the Uno doesn’t have.

Most Nanos sold in India are clones with a CH340 USB chip and the old bootloader. If uploads fail with “not in sync”, that one Processor setting is almost always the fix.

Power it from USB, 5 V on the 5V pin, or 7–12 V on VIN. The 3V3 pin comes from the USB chip and supplies only a few tens of mA — fine for a sensor’s logic, not for a Wi-Fi module.

Interactive pinout

Hover or tap a pin for its functions and traps. Filter to light up every I2C, ADC or boot pin.

Safe for most uses
Works, with a caveat
Avoid unless you know why
Power / control

A6 and A7 are analog-only. They read voltages with analogRead() but cannot be used with digitalRead() or as outputs.

20 mA per pin, 200 mA for the whole chip. LEDs with a resistor are fine. Relays, motors and buzzers need a driver module or transistor.

Breadboard friendly, Uno compatible. Same chip and pins as the Uno, so Uno sketches and libraries work unchanged — just pick the Nano board in the IDE.

Set up your computer

Install Arduino IDE 2.x from arduino.cc.
Boards Manager → install Arduino AVR Boards (we compile against avr 1.8.8).
Tools → Board → Arduino Nano (Tools → Processor → ATmega328P, or "Old Bootloader" for most clones), then pick the port that appears when you plug the board in.

Your platformio.ini:

platformio.iniOutput

[env:nano]
platform = atmelavr
board = nanoatmega328
framework = arduino
monitor_speed = 9600

[env:nano]
platform = atmelavr
board = nanoatmega328
framework = arduino
monitor_speed = 9600

First program

Verified — core avr 1.8.8, 3 Nov 2026Compile-only

blink-nano.inoArduino C++Open in Playground Flash

// First program for the Arduino Nano: blink the on-board "L" LED (D13).
// Clones often need Tools → Processor → "ATmega328P (Old Bootloader)" to upload.
void setup() {
  Serial.begin(9600);
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.println(F("FlashReady: Nano blink"));
}

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

// First program for the Arduino Nano: blink the on-board "L" LED (D13).
// Clones often need Tools → Processor → "ATmega328P (Old Bootloader)" to upload.
void setup() {
  Serial.begin(9600);
  pinMode(LED_BUILTIN, OUTPUT);
  Serial.println(F("FlashReady: Nano blink"));
}

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