# Lesson 1 - Blinking LED

Lesson 1 Blinking LED

Introduction

In this lesson, you will learn how to use the SunFounder Uno board by turning on an LED and making it blink once per second.

Components

- 1 * SunFounder Uno board

- 1 * USB cable

- 1 * Resistor (220Ω)

- 1 * 1 LED

- Jumper wires

- 1 * Breadboard

Principle

LED

A light-emitting diode (LED) is a semiconductor device which can turn electric energy into light energy via PN junctions. By wavelength, it can be categorized into laser diode, infrared light-emitting diode and visible light-emitting diode which is usually known as light-emitting diode (LED). LEDs are usually red, yellow, green, blue, or color-changing. Color-changing LEDs can change their color with different voltages.

Before building any circuit, you should know the parameters of the components in the circuit, such as their operating voltage, operating circuit, etc. You should connect a current-limiting resistor when an LED is used or else the LED can become burned due to excessive current. In this experiment, the operating voltage of the LED is between 1.5V and 2.0V and the operating current is between 10mA and 20mA. The SunFounder Uno board can supply 5V power, the LED we choose works at 1.7V, 15mA. The current-limiting resistance equals total voltage subtracted by LED voltage, then divided by current. In this case, that would be (5-1.7)/0.015. Thus, the current-limiting resistance equals 220Ω.

Experimental Procedures

Step 1: Build the circuit

The schematic diagram:

Step 2: Program: Use the Arduino program on the computer. You can download that for free at www.arduino.cc Or use a schoolcomputer where it is already installed. Once open, copy/paste the code in this file:

Arduino Code

Step 3: Compile the code

Step 4: Upload the sketch to the SunFounder Uno board

You should now see the LED blinking.