To make LED turning ON using Arduino Uno in Wokwi Simulator, Visit: www.wokwi.com Choose: Arduino (Uno, Mega, Nano) Scroll Down and Choose Arduino Uno: Click on + Sign: Search LED: Remember Straight Pin is Cathode Pin, that is negativc terminal and Bended Pin is Anode Pin, that is positive terminal. Connect Negative Terminal of LED to GND and Positive Terminal of LED to 13: Write this code on Left Hand Side inside sketch.ino: void setup () { // put your setup code here, to run once: pinMode ( 13 , OUTPUT ); } void loop () { // put your main code here, to run repeatedly: digitalWrite ( 13 , HIGH ); } Click on Green Play Button to start the simulation: Now, LED is turning on. Thanks.