25.5.6 LED Light
LED (Light-emitting diode) is widely used as a oupput device for determining whether electricity flows through a specific line when constructing an electronic circuit. LED lights up when the voltage is applied, so it can indicate whether the specific GPIO port of the Raspberry Pi is high or low, and can determine if electricity flows on a certain line of the circuit. The GPIO port of Raspberry PI does not provide high power enough to drive high-brightness LED, so buy low-power LED (typical LED) when purchasing LED.