#include <SoftwareSerial.h>

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

void setup() {
  Serial.begin(9600);      // For Serial Monitor
  BTSerial.begin(9600);    // Default HC-05 baud rate
  Serial.println("HC-05 Bluetooth module ready. Type something...");
}

void loop() {
  // Read data from HC-05
  if (BTSerial.available()) {
    char c = BTSerial.read();
    Serial.write(c);
  }

  // Read data from Serial Monitor
  if (Serial.available()) {
    char c = Serial.read();
    BTSerial.write(c);
  }
}