How to Use Bluetooth Module with Arduino: Beginner’s Guide

What is the Bluetooth Module?

Bluetooth module is a useful component in electronics projects, enabling wireless communication between devices. These modules can be integrated into Arduino projects to send and receive data without physical connections. Bluetooth technology is commonly used in applications such as wireless speakers, smart home devices, and personal gadgets. In the Arduino ecosystem, Bluetooth modules like the HC-05, HC-06, and HM-10 are widely used to add wireless communication capabilities. These modules differ in their features and compatibility, but they all serve the same purpose of enabling easy wireless communication.

Why Use a Bluetooth Module with Arduino?

Adding a Bluetooth module to Arduino projects opens up a world of wireless control and communication possibilities. It allows you to control devices remotely via a smartphone, tablet, or PC without physical connections. This can be particularly useful for controlling robots, monitoring sensors, or creating Internet of Things (IoT) devices. Bluetooth modules are easy to integrate with Arduino and offer a versatile and cost-effective solution for wireless communication. Some popular applications include Bluetooth-controlled home automation, remote monitoring systems, and wireless data logging.

Types of Bluetooth Modules

There are different types of Bluetooth modules commonly used with Arduino. The HC-05 and HC-06 are the most common modules. The HC-05 is a versatile module capable of both enslaver and enslaved person modes, meaning it can initiate and receive Bluetooth connections. The HC-06, however, can only operate in slave mode, which means it can only receive connections. Another commonly used Bluetooth module is the HM-10, which supports Bluetooth Low Energy (BLE). BLE is more energy-efficient, making it ideal for battery-powered applications such as wearables and IoT devices.

How the Bluetooth Module Works

Bluetooth modules work by transmitting and receiving data wirelessly using the Bluetooth protocol. The communication happens over a serial connection using Universal Asynchronous Receiver-Transmitter (UART). The Bluetooth module connects with Arduino to its TX (transmit) and RX (receive) pins. Data sent from the Arduino is transmitted via the TX pin of the Bluetooth module, while data received wirelessly is fed to the Arduino’s RX pin. This allows two-way communication between the Arduino and another Bluetooth device, such as a smartphone or computer.

Connecting a Bluetooth module to an Arduino

Wiring Diagram

Connecting a Bluetooth module to an Arduino is simple. Typically, the Bluetooth module’s TX pin connects to the Arduino’s RX pin, while the RX pin connects to the TX pin on the Arduino. The VCC pin supplies power to the module, usually 3.3V or 5V, depending on the module, and the GND pin connects to the Arduino’s ground.

Arduino Code

Here’s a basic example of establishing a Bluetooth connection between the module and a smartphone using the Arduino’s Serial communication.

#include <SoftwareSerial.h>

// Create a Bluetooth serial object
SoftwareSerial Bluetooth(10, 11); // RX, TX

void setup() {
  Serial.begin(9600); // Start Serial monitor communication
  Bluetooth.begin(9600); // Start Bluetooth communication at 9600 baud rate
  Serial.println("Bluetooth module ready");
}

void loop() {
  // Check if data is available from the Bluetooth module
  if (Bluetooth.available()) {
    char data = Bluetooth.read(); // Read the data
    Serial.write(data); // Display the data on the Serial monitor
  }

  // Check if data is available from the Serial monitor
  if (Serial.available()) {
    char data = Serial.read(); // Read the data
    Bluetooth.write(data); // Send the data to the Bluetooth module
  }
}

This code sets up communication between the Arduino and Bluetooth module, allowing the user to send data back and forth between a smartphone and the Arduino using a terminal app. You can expand this code for more advanced applications, like controlling devices or sending sensor data.

Try the Arduino Bluetooth Control as the terminal app, Because it is very simple and easy to use for beginners.

1. Connect your mobile phone with the HC-05 Bluetooth module.
2. Then connect your HC-05 to the Arduino Bluetooth Control app.
3. Go to the terminal and then you can send data to Arduino, Also you can send data to the Bluetooth module using the serial monitor.

Conclusion

Bluetooth modules enhance the interactivity and flexibility of Arduino projects by enabling wireless communication. They are simple to integrate and offer many possibilities for applications such as home automation, remote control systems, and IoT projects. Using Bluetooth with Arduino allows for greater control and monitoring of your projects via smartphones or other devices. You can explore more advanced use cases for future projects, like building Bluetooth-controlled robots, wireless data logging systems, or BLE-powered IoT devices.