The LM35 temperature sensor and red led are powered with 5V from the Arduino board. How does the circuit works? As you can see in the sketch on the first line I included the LiquidCrystal library ...

We’d seen it done with buttons, switches, gestures, capacitive touch, and IR remote, but never like this. [electron_plumber] made an LED that can be blown out like a candle, and amazingly it … ...