Things you need: Arduino Nano, 3V LED, 100 Ohm Resistor

To power up the Arduino Nano board, you can use USB cable or an external power supply (7V ~ 12V DC) by connecting positive pin to VIN and and negative to the ground. Please see my previous post about powering up Arduino Nano here: https://blogs.webservice.lk/2020/03/17/powering-up-arduino-nano/

To connect LED, use LED’s positive end to the one end of resistor and other end to Arduino Nano’s digital pin 13 & negative end to the  one of Arduino Nano’s ground pin. Please see the picture above.

Now circuit making part is done, Let’s do the programing.

int ledPin =  13;// the number of the LED pin

void setup() {
  // set the digital pin as output:
  pinMode(ledPin, OUTPUT);
}

void loop() {
  digitalWrite(ledPin, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(ledPin, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);
}

Upload above sketch to the Arduino Nano and see the result. Led will blink with the 1 second delay.

The Arduino Nano is a small, complete, and breadboard-friendly board based on the ATmega328P (Arduino Nano 3.x). It has more or less the same functionality of the Arduino Duemilanove, but in a different package. It lacks only a DC power jack, and works with a Mini-B USB cable instead of a standard one.

The Arduino Nano can be powered via the Mini-B USB Jack (5V) connection. 

The Arduino Nano accepts the 7V to 12V input power from the Vin pin (pin30).

If you want to supply regulated power, then a 5V regulated adapter needs to feed the +5V pin (pin27) instead.

The power source is automatically selected to the highest voltage source if you input multiple power inputs.