Arduino in-built LED is not turning off I have an Arduino Uno whose LED, which is connected to  pin 13, is not turning off and it always stays on, and it annoys me.



Touching any exposed pins turns off the LED after removing my hands from the pins it turns back on slowly.

However it works perfectly with the programs. This program does turn the LED off and it stays that way while the program is running.

void loop() {
  digitalWrite(13, LOW);         
}


When I upload other programs that don't use pin 13 then it stays on again. How can I fix this?
If you don't tell it to turn off, it behaves "as it wants". If you don't write a 0 on its pin, how can you force it to stay shut down?

If you want it to be in an off state, force it: in your setup function write

pinMode(13, OUTPUT);
digitalWrite(13, LOW);


No need to refresh it every loop, just in the setup.