Configure HC-06 Demo

Arduino code

// Configuring HC-06 Via Bluetooth Demo
// By keuwlsoft:  www.keuwl.com  30th Sept 2015
// cc Attribution-ShareAlike

// Used with an Android device running keuwlsofts 'Bluetooth Electronics'
// app with the 'Configure HC-06 demo' panel.  Program baud rate, name and  
// pin on a second HC-06 module connected to the software serial. 

#include <SoftwareSerial.h> //library for software serial

//define software serial: RX on Pin 8, TX on Pin 9
SoftwareSerial softSerial(8, 9); 

long baud_rates[]={1200,2400,4800,9600,19200,38400,57600,115200};
int baud_index=3;
char BluetoothData; // the data received from bluetooth serial link
boolean found_baud=false; //Flag to indicate if baud rate has been detected

void setup() {
   
  Serial.begin(9600); //Initialise serial for communicating to android device 
}

void loop() {

 if (Serial.available()){
    BluetoothData=Serial.read(); //Get next character from bluetooth
    
  //Find Baud Rate
    if(BluetoothData=='F') find_baud_rate();
  
  //Set Baud Rate
    if(BluetoothData>48&&BluetoothData<57){ //chars '1' to '8'
      if (!found_baud) find_baud_rate();  
      softSerial.print("AT+BAUD"+String(BluetoothData-48));
      delay(1500);
      if (softSerial.available()) Serial.println("Response="+softSerial.readString());
      softSerial.end();
      baud_index=BluetoothData-49;
      softSerial.begin(baud_rates[baud_index]); //Initialise software serial at new rate
    }
    
  //Set New Name or Custom Command  
    if(BluetoothData=='N'||BluetoothData=='C'){
      String str=Serial.readString();
      if (BluetoothData=='N')str="AT+NAME"+str;
      if (!found_baud) find_baud_rate();  
      softSerial.print(str);
      delay(1500);
      if (softSerial.available()) Serial.println("Response="+softSerial.readString());
    }
  
  //Set New Pin  
    if(BluetoothData=='P'){
      int pin=Serial.parseInt();
      if (!found_baud) find_baud_rate();  
      softSerial.print("AT+PIN"+ String(pin));
      delay(1500);
      if (softSerial.available()) Serial.println("Response="+softSerial.readString());
    }

 }
}

//Function to loop through the baud rates until a response is obtained
void find_baud_rate(){
 
  found_baud=false;
  baud_index=-1;
  while(!found_baud&&baud_index<8){
    baud_index++;
    softSerial.begin(baud_rates[baud_index]); //Initialise software serial
    Serial.println("Testing "+String(baud_rates[baud_index])+" Baud ...");
    delay(100);
    softSerial.print("AT");
    delay(1500);
    if (softSerial.available()){
      found_baud=true;
      Serial.println(softSerial.readString()+" at "+String(baud_rates[baud_index])+" Baud");
    }
    if (!found_baud) softSerial.end();
  }
  if (!found_baud) softSerial.begin(9600); //If not found, try at 9600 anyway
}