LED module

Just as printing “Hello, world!” is the first step in learning to program, using a program to drive an LED is the traditional introduction to learning physical programming.

Required Components

In this project, we need the following components.

It’s definitely convenient to buy a whole kit, here’s the link:

Name

ITEMS IN THIS KIT

LINK

Elite Explorer Kit

300+

Elite Explorer Kit

You can also buy them separately from the links below.

COMPONENT INTRODUCTION

PURCHASE LINK

Arduino Uno R4 WiFi

-

Breadboard

BUY

Jumper Wires

BUY

Resistor

BUY

LED

BUY

Wiring

../_images/10-led_bb.png

Schematic Diagram

../_images/10_led_schematic.png

Code

Note

  • You can open the file 10-led.ino under the path of elite-explorer-kit-main\basic_project\10-led.

  • Or copy this code into Arduino IDE.

After the code is uploaded successfully, you will see the LED connected to digital pin 9 of the Arduino board start to blink. The LED will turn on for half a second and then turn off for another half a second, repeating this cycle continuously as the program runs.

Code Analysis

Here, we connect the LED to the digital pin 9, so we need to declare an int variable called ledpin at the beginning of the program and assign a value of 9.

const int ledPin = 9;

Now, initialize the pin in the setup() function, where you need to initialize the pin to OUTPUT mode.

void setup() {
    pinMode(ledPin, OUTPUT);
}

In loop(), digitalWrite() is used to provide 5V high level signal for ledpin, which will cause voltage difference between LED pins and light LED up.

digitalWrite(ledPin, HIGH);

If the level signal is changed to LOW, the ledPin’s signal will be returned to 0 V to turn LED off.

digitalWrite(ledPin, LOW);

An interval between on and off is required to allow people to see the change, so we use a delay(1000) code to let the controller do nothing for 1000 ms.

delay(1000);