How to Interface a Bluetooth Module with an Arduino

Interfacing a Bluetooth module with an Arduino board is a popular project for electronics enthusiasts. In this article, we will guide you on how to interface a Bluetooth module with an Arduino board.

Requirements:

• Arduino board (Uno, Nano, or Mega)
• HC-05 Bluetooth module
• Jumper wires
• Breadboard
• USB cable

Steps:

1. Connect the Bluetooth Module to the Arduino Board

Connect the Bluetooth module to the Arduino board using jumper wires. The HC-05 Bluetooth module has six pins: VCC, GND, TXD, RXD, STATE, and EN.

• VCC to 5V pin on Arduino board
• GND to GND pin on Arduino board
• TXD to RX pin on Arduino board
• RXD to TX pin on Arduino board
• STATE to any digital pin on Arduino board (we will use pin 7)
• EN to 3.3V pin on Arduino board

2. Install the Bluetooth Library

To interface the Bluetooth module with the Arduino board, we need to install the SoftwareSerial library. Open the Arduino IDE and go to Sketch > Include Library > Manage Libraries. Search for SoftwareSerial and install it.

3. Upload the Code to Arduino Board

Copy the following code and upload it to the Arduino board:

scssCopy code#include <SoftwareSerial.h>

SoftwareSerial BTSerial(10, 11); // RX, TX

void setup() {
  Serial.begin(9600);
  BTSerial.begin(38400); // HC-05 default baud rate
  pinMode(7, INPUT);
}

void loop() {
  if (BTSerial.available()) {
    Serial.write(BTSerial.read());
  }
  if (Serial.available()) {
    BTSerial.write(Serial.read());
  }
  if (digitalRead(7) == HIGH) {
    BTSerial.println("AT");
    delay(500);
    while (BTSerial.available()) {
      Serial.write(BTSerial.read());
    }
  }
}

4. Test the Bluetooth Module

Open the Serial Monitor in the Arduino IDE and set the baud rate to 9600. Type some text in the Serial Monitor and press Enter. You should see the same text on your phone or other Bluetooth-enabled device connected to the HC-05 module.

To test the AT commands, set the digital pin 7 to HIGH and send the “AT” command. You should see the response from the HC-05 module in the Serial Monitor.

Conclusion

Interfacing a Bluetooth module with an Arduino board is a simple project that can be used in various applications, such as remote control and sensor data logging. By following the steps above, you can interface a Bluetooth module with your Arduino board and establish wireless communication between your project and other Bluetooth-enabled devices.

As a professional manufacturer of low power Bluetooth module, Tecksay has independently developed and produced a number of BLE Bluetooth modules that have been applied to many industries. With more than ten years of industry experience, Tecksay can customize BLE embedded solutions for customers from design, project management, function customization, system development and other aspects.