HC-05 sends endless println messages and does not respond

Projects Programming
3

I have done some experiments with your program codes with a HC-05 and an UNO; I could not arrive at any concrete conclusion. When I have changed your if-else structure into switch-case structure and moved the SRX, STX pins to 10, 11, I have seen some improvements. Given below the program codes; you may play around.

#include <SoftwareSerial.h>
#include <AFMotor.h>

SoftwareSerial BTSerial(10, 11);  //SRX, STX of UNO
AF_DCMotor Motor1(1);
AF_DCMotor Motor2(2);
AF_DCMotor Motor3(3);
AF_DCMotor Motor4(4);
//char ch = ' ';

void setup()
{

  Serial.begin(9600);
  BTSerial.begin(9600);
  pinMode(13, OUTPUT);
  digitalWrite(13, LOW);
  //  BTSerial.flush();
}

void loop()
{
  if (BTSerial.available() > 0)
  {
    char ch = BTSerial.read();
  //  BTSerial.print("Received: ");
    BTSerial.write(ch);
    Serial.println(ch);
    //while(1);
    switch (ch)
    {
      case 'C':
        {
           Motor1.setSpeed(255);
          Motor1.run(BACKWARD);
          Motor2.setSpeed(255);
          Motor2.run(BACKWARD);
          Motor3.setSpeed(255);
          Motor3.run(BACKWARD);
          Motor4.setSpeed(255);
          Motor4.run(BACKWARD);
          break;
        }
      case  'D':
      {
        Motor1.setSpeed(0);
        Motor1.run(BRAKE);
        Motor2.setSpeed(0);
        Motor2.run(BRAKE);
        Motor3.setSpeed(0);
        Motor3.run(BRAKE);
        Motor4.setSpeed(0);
        Motor4.run(BRAKE);
        break;
      }
    case  'E':
    {
        digitalWrite(13, HIGH);
        break;
      }
      
      case  'F':
      {
        digitalWrite(13, LOW);
        break;
      }
   }
  }
}