Bluetooth with HC-05/HC-06 module in Arduino - Mini Project: Build & Apply

Bluetooth with HC-05/HC-06 module

📖 Scenario: You want to control an LED on your Arduino board using a Bluetooth module like HC-05 or HC-06. This project will help you set up the Bluetooth communication and turn the LED on or off by sending simple commands from your phone or computer.

🎯 Goal: Build a simple Arduino program that reads data from the HC-05/HC-06 Bluetooth module and turns an LED on or off based on the received command.

📋 What You'll Learn

Create a variable for the LED pin number

Create a variable for the Bluetooth serial communication

Write code to read data from the Bluetooth module

Control the LED based on the received data

Print the LED status to the serial monitor

💡 Why This Matters

🌍 Real World

Bluetooth modules like HC-05 and HC-06 are commonly used to add wireless control to devices such as home automation systems, robots, and wearable gadgets.

💼 Career

Understanding Bluetooth communication and Arduino programming is useful for embedded systems developers, IoT engineers, and hobbyists working on wireless device projects.

1

Set up the LED pin

Create an integer variable called ledPin and set it to 13. Then, in the setup() function, set the ledPin as an output using pinMode.

Arduino

int ledPin = 13;

void setup() {
  // Set ledPin as output
  // Your code here
}

void loop() {
  // Your code here
}

Need a hint?

Use pinMode(ledPin, OUTPUT); inside setup() to prepare the LED pin.

2

Initialize Bluetooth serial communication

Create a SoftwareSerial object called bluetooth using pins 10 for RX and 11 for TX. In the setup() function, start the bluetooth serial communication at 9600 baud rate. Also, start the default serial communication at 9600 baud rate.

Arduino

#include 

int ledPin = 13;
SoftwareSerial bluetooth(10, 11); // RX, TX

void setup() {
  pinMode(ledPin, OUTPUT);
  // Start bluetooth serial at 9600
  // Start serial monitor at 9600
  // Your code here
}

void loop() {
  // Your code here
}

Need a hint?

Use bluetooth.begin(9600); and Serial.begin(9600); inside setup().

3

Read Bluetooth data and control LED

In the loop() function, check if bluetooth.available() is greater than zero. If yes, read the incoming byte using bluetooth.read() and store it in a variable called incomingByte. If incomingByte is the character '1', turn the LED on using digitalWrite(ledPin, HIGH). If incomingByte is the character '0', turn the LED off using digitalWrite(ledPin, LOW). Also, print "LED ON" or "LED OFF" to the serial monitor accordingly.

Arduino

#include 

int ledPin = 13;
SoftwareSerial bluetooth(10, 11); // RX, TX

void setup() {
  pinMode(ledPin, OUTPUT);
  bluetooth.begin(9600);
  Serial.begin(9600);
}

void loop() {
  if (bluetooth.available() > 0) {
    // Read incoming byte
    // Your code here
  }
}

Need a hint?

Use bluetooth.read() to get the data and digitalWrite to control the LED.

4

Test and display LED status

Print the message "Waiting for Bluetooth command..." once in the setup() function to the serial monitor. This will help you know the program is ready.

Arduino

#include 

int ledPin = 13;
SoftwareSerial bluetooth(10, 11); // RX, TX

void setup() {
  pinMode(ledPin, OUTPUT);
  bluetooth.begin(9600);
  Serial.begin(9600);
  // Print waiting message
  // Your code here
}

void loop() {
  if (bluetooth.available() > 0) {
    char incomingByte = bluetooth.read();
    if (incomingByte == '1') {
      digitalWrite(ledPin, HIGH);
      Serial.println("LED ON");
    } else if (incomingByte == '0') {
      digitalWrite(ledPin, LOW);
      Serial.println("LED OFF");
    }
  }
}

Need a hint?

Use Serial.println("Waiting for Bluetooth command..."); inside setup().