HC-05 Bluetooth

// HC-05 Bluetooth basic example for Arduino Uno
// Wiring:
// HC-05 VCC -> 5V
// HC-05 GND -> GND
// HC-05 TXD -> Arduino D0 (RX)
// HC-05 RXD -> Arduino D1 (TX)
//
// Open the Serial Monitor at 9600 baud and set line ending to "No line ending".
// Anything you type will be sent to the HC-05 and echoed back from the Arduino.

void setup() {
  Serial.begin(9600);   // USB serial monitor
  while (!Serial) {
    ; // Needed on boards with native USB; harmless on Uno
  }
}

void loop() {
  // If data comes from the USB Serial Monitor, forward it to the HC-05 UART pins.
  while (Serial.available() > 0) {
    char c = (char)Serial.read();
    Serial.write(c);   // Echo locally so beginners can see what was sent
    Serial.print("[Sent to HC-05] ");
    Serial.println(c);

    // On Arduino Uno, hardware Serial is shared with the USB interface.
    // This simple demo keeps the sketch compilable and focuses on wiring.
    // For a real HC-05 UART data link, use SoftwareSerial on different pins.
  }
}