void setup() pinMode(13, OUTPUT);

void loop() digitalWrite(13, HIGH); delay(1000); digitalWrite(13, LOW); delay(1000);

![Mental image: Uno with LED on D13] In Arduino IDE :

Arduino Uno Library For Proteus Online

void setup() pinMode(13, OUTPUT);

void loop() digitalWrite(13, HIGH); delay(1000); digitalWrite(13, LOW); delay(1000);

![Mental image: Uno with LED on D13] In Arduino IDE :