Interfacing Bluetooth module (e.g. HC05)- receiving data from mobile phone on Arduino and display on LCD.

Aim:

To interface an HC-05 Bluetooth module with Arduino, receive data from a mobile phone, and display the received data on a 16×2 LCD.

Components Required:

• Arduino UNO
• HC-05 Bluetooth Module
• 16×2 LCD with I2C module
• Jumper wires
• USB cable
• Android mobile phone

Connections:

HC-05	Arduino UNO
VCC	5V
GND	GND
TXD	D10
RXD	D11

I2C LCD:

LCD	Arduino UNO
VCC	5V
GND	GND
SDA	A4
SCL	A5

Arduino Program

#include <LiquidCrystal_I2C.h>
#include <SoftwareSerial.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);
SoftwareSerial BT(10, 11);   // RX, TX
void setup()
{
  Serial.begin(9600);
  BT.begin(9600);
  lcd.init();
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Waiting...");
}
void loop()
{
  if (BT.available())
  {
    String data = BT.readStringUntil('\n');
    data.trim();
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("Bluetooth Data:");
    lcd.setCursor(0, 1);
    lcd.print(data);
    Serial.println(data);
  }
}

Procedure

1. Connect the HC-05 Bluetooth module and I2C LCD to Arduino UNO as shown in the circuit diagram.
2. Upload the Arduino program.
3. Pair the mobile phone with HC-05.
4. The default PIN is generally 1234 or 0000.
5. Open a Bluetooth Terminal application on the mobile phone.
6. Connect the application to HC-05.
7. Type a message such as “Hello Arduino” and press Send.
8. The HC-05 receives the message and transfers it to Arduino.
9. Arduino displays the received message on the 16×2 LCD.

Working Principle

Mobile Phone → Bluetooth (HC-05) → Arduino UNO → I2C LCD

When a user sends text from the mobile phone, HC-05 receives the data wirelessly. Arduino reads this data through the serial communication pins and displays it on the LCD.

Result

The HC-05 Bluetooth module was successfully interfaced with Arduino UNO, and data received from a mobile phone was displayed on the 16×2 LCD.