LED

Introduction

A Light Emitting Diode (LED) is a type of semiconductor diode that emits light when a current flows through it. LEDs are commonly used in electronic projects to provide visual feedback to the user. They are available in a variety of colors, and can be used to indicate the status of a system, provide illumination, or create visual effects.

When using an LED in a circuit, you must connect it to a current-limiting resistor to prevent it from drawing too much current and burning out. The value of the resistor depends on the forward voltage and forward current of the LED, and the supply voltage of the circuit.

Pin Description

An LED has two pins: an anode and a cathode. The anode is the positive pin, and the cathode is the negative pin. You connect the anode to a digital output pin on a microcontroller, and the cathode to a current-limiting resistor, which is then connected to the ground pin. When you apply a high signal to the anode, the LED emits light.

Code Example

The following code example demonstrates how to turn an LED on and off using a digital output pin on an Arduino board.

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12

#define LED_PIN 13 // define the LED pin

void setup() {
  pinMode(LED_PIN, OUTPUT); // set the LED pin as an output
}

void loop() {
  digitalWrite(LED_PIN, HIGH); // turn the LED on
  delay(1000); // wait for 1 second
  digitalWrite(LED_PIN, LOW); // turn the LED off
  delay(1000); // wait for 1 second
}

In this example, we use the digitalWrite function to apply a high signal to the LED pin, causing the LED to emit light. We then wait for 1 second using the delay function, and then apply a low signal to the LED pin to turn the LED off.