Q:

Arduino led on and off program using hc05 bluetooth module. Bluetooth doesn't recieve what I send using bluetooth terminal app

I have tried to connect my arduino with hc-05, and run a simple 'LED on and off' program. When I disconnected the rx and tx pins and tried sending the commands using serial monitor in arduino, and it worked perfectly alright. But when I connected the rx and tx pins of hc-05 bluetooth module, and used the Bluetooth terminal app from playstore to send and recieve commands, whatever I send doesn't get recieved the same, instead I get weird characters on my serial monitor. Someone please help me solve this. I have included the arduino code and the screen shots of the serial monitor and the app.
char junk;
String inputString="";

void setup()
{
Serial.begin(9600);
pinMode(13, OUTPUT);
}

void loop()
{
  if(Serial.available()){
  while(Serial.available())
    {
      char inChar = (char)Serial.read();
      inputString += inChar;
    }
    Serial.println(inputString);
    while (Serial.available() > 0)  
    { junk = Serial.read() ; }
    if(inputString == "a"){ 
      digitalWrite(13, HIGH);  
    }else if(inputString == "b"){  
      digitalWrite(13, LOW);
    }
    inputString = "";
  }
}

SERIAL MONITOR ARDUINO
Bluetooth Terminal

A:

i have some questions if you are using hc-05 it connected with  app with this device with password. if you are sending data from terminal it working fine but hc-05 not working so check hc-05 with terminal .

