Published September 11, 2023 © Apache-2.0

How to Control LED From Windows PC Using Arduino

I will guide you through the step-by-step process of controlling an LED from your Windows computer using an Arduino board.

BeginnerFull instructions provided2 hours229

How to Control LED From Windows PC Using Arduino

Things used in this project

Hardware components

Arduino Uno

1K Ohm Resister

LED

Breadboard

Jumper Wire

Software apps and online services

Arduino IDE

IoT Control Tower

Story

I will guide you through the process of how to control LED from a Windows PC using an Arduino board. Whether you’re a beginner looking to learn the basics of Arduino or an enthusiast seeking a fun DIY project, this blog post will provide you with the knowledge and tools you need to get started. Let’s dive into the exciting world of Arduino-powered LED control using a PC.

Controlling LED From PC

The idea behind controlling the LED from a Windows PC is serial communication, Serial communication is a fundamental concept in electronics and programming, and it plays a key role in controlling the LED from a Windows PC using an Arduino.

The Basics of Serial Communication: Serial communication is a method used to transfer data between two devices or systems one bit at a time, over a single wire or a pair of wires. It’s a common way to establish a data link between microcontrollers like Arduino and computers or other devices. In the case of Arduino and a Windows PC, this communication happens over a USB cable.

Serial Communication In Arduino:

In Arduino, serial communication is implemented using the Serial library. The Arduino board has a built-in hardware UART (Universal Asynchronous Receiver/Transmitter) that allows it to send and receive serial data.
The Serial library provides functions for sending and receiving data using the UART. The most commonly used functions are Serial.begin(), Serial.print(), and Serial.read().
Serial.begin(baudRate) initializes the serial communication at a specific baud rate, which determines the speed of data transmission. Both the Arduino and the PC must use the same baud rate for successful communication.
Serial.print() is used to send data from the Arduino to the PC, and Serial.read() is used to read data sent from the PC to the Arduino.

How Serial Communication Controls The LED:

Arduino Code: You write an Arduino sketch (program) that listens for incoming serial data from the PC. You define specific commands that the Arduino should recognize, such as “1” to turn the LED on and “0” to turn it off.
PC Interaction: Using the IoT Control Tower Windows app (free & open source) you can configure and send commands to the Arduino board.

Arduino Response: When the Arduino receives a command via serial communication, it interprets the command and takes the corresponding action. For example, upon receiving “1, ” it turns on the LED, and upon receiving “0, ” it turns it off.

Troubleshooting And Tips

Arduino Not Recognized by Windows:

Issue: The Arduino board is not recognized by Windows, and the COM port is not visible.

Troubleshooting:

Ensure that the USB cable is securely connected to both the Arduino board and the PC.
Try using a different USB cable or USB port on your PC.
Install or update the Arduino drivers (if not automatically done by Windows).
Troubleshooting: Ensure that the USB cable is securely connected to both the Arduino board and the PC.Try using a different USB cable or USB port on your PC. Install or update the Arduino drivers (if not automatically done by Windows).
Arduino Not Recognized by Windows:Issue: The Arduino board is not recognized by Windows, and the COM port is not visible.
Troubleshooting: Ensure that the USB cable is securely connected to both the Arduino board and the PC.Try using a different USB cable or USB port on your PC. Install or update the Arduino drivers (if not automatically done by Windows).

Incorrect COM Port Selection:

Issue: Selecting the wrong COM port in the Arduino IDE.

Troubleshooting:

Double-check the COM port selected in the Arduino IDE under the “Tools” menu. It should match the COM port assigned to the Arduino by Windows.
If unsure, disconnect and reconnect the Arduino, and check the COM port list again.
Troubleshooting: Double-check the COM port selected in the Arduino IDE under the “Tools” menu. It should match the COM port assigned to the Arduino by Windows. If unsure, disconnect and reconnect the Arduino, and check the COM port list again.
Incorrect COM Port Selection:Issue: Selecting the wrong COM port in the Arduino IDE.Troubleshooting: Double-check the COM port selected in the Arduino IDE under the “Tools” menu. It should match the COM port assigned to the Arduino by Windows. If unsure, disconnect and reconnect the Arduino, and check the COM port list again.

LED Doesn’t Respond to Commands:

Issue: The LED connected to the Arduino doesn’t respond to the commands sent from the PC.

Troubleshooting:

Double-check your wiring and connections. Ensure the LED is properly connected to the correct pins on the Arduino.
Review your Arduino code for any errors in command interpretation or LED control logic.
Verify that you’re sending the correct commands from the PC.
Troubleshooting:Double-check your wiring and connections. Ensure the LED is properly connected to the correct pins on the Arduino.Review your Arduino code for any errors in command interpretation or LED control logic.Verify that you’re sending the correct commands from the PC.
LED Doesn’t Respond to Commands:Issue: The LED connected to the Arduino doesn’t respond to the commands sent from the PC.Troubleshooting:Double-check your wiring and connections. Ensure the LED is properly connected to the correct pins on the Arduino.Review your Arduino code for any errors in command interpretation or LED control logic. Verify that you’re sending the correct commands from the PC.

Code

Sketch for Controlling LED using Windows PC

int RED_PIN = 5;
int BLUE_PIN = 6;
int GREEN_PIN =7;

String inputString;

void setup() {
  // put your setup code here, to run once: 5-0
  Serial.begin(9600);
  
  pinMode(RED_PIN, OUTPUT);
  pinMode(BLUE_PIN, OUTPUT);
  pinMode(GREEN_PIN, OUTPUT);
}

void loop() {
  
 inputString = Serial.readString();

  if(inputString != ""){
  
  int delimiterPos = inputString.indexOf('-');

    if (delimiterPos != -1) {
    String pinString = inputString.substring(0, delimiterPos);  
    String stateString = inputString.substring(delimiterPos + 1);  
    
    int pinNumber = pinString.toInt(); 
    int command = stateString.toInt(); //0 = Off or 1 = ON

    if (command == 1) {
      digitalWrite(pinNumber, HIGH);
    } else if (command == 0) {
      digitalWrite(pinNumber, LOW);
    }  
  }  
  }

}

Credits

Rajiv Sharma

17 projects • 71 followers

Having more than 10 years of experience in IoT and software technology. Founded IoTBoys to share knowledge with IoT enthusiasts.

IoTBoys

9 projects • 115 followers

Watch, Learn and Built IoT projects | DIY IoT Projects | IoT Projects for College Student.

How to Control LED From Windows PC Using Arduino