Arduino RC Car using Bluetooth HC06 and Motor Drive L9110S

#define AIA 5 //mandroso
#define AIB 6 //mihemotra
#define BIA 8 //havia
#define BIB 7 //havanana
#define MS 12 // mijanona ny moteur direction
#define JI 10 // jiro
#define KX 9  //klaxon

char vertical; //mandroso sa mihemotra
char horizontal; //havia sa havanana
int ds = 0; //direction state

byte speed = 130;
char cmd;    // incoming data
void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(AIA, OUTPUT);
  pinMode(AIB, OUTPUT);
  pinMode(BIA, OUTPUT);
  pinMode(BIB, OUTPUT);
  pinMode(MS, INPUT);
  pinMode(JI, OUTPUT);
  digitalWrite(AIA, LOW);
  digitalWrite(AIB, LOW);
  analogWrite(BIA, 0);
  analogWrite(BIA, 0);
  digitalWrite(JI, LOW);
}

void loop() {



  // put your main code here, to run repeatedly:
  if (Serial.available() > 0)
  {
    cmd = Serial.read();
    
    switch (cmd)
    {
      
      case 'F':
        digitalWrite(AIA, HIGH);
        break;
      case 'B':
        digitalWrite(AIB, HIGH);
        break;
      case 'L':
        analogWrite(BIA, 0);
  analogWrite(BIB, speed);
        break;
      case 'R':
        analogWrite(BIA, speed);
  analogWrite(BIB, 0);
        break;
      case 'G':
        digitalWrite(AIA, HIGH);
        analogWrite(BIA, 0);
  analogWrite(BIB, speed);
        break;
      case 'I':
        digitalWrite(AIA, HIGH);
        analogWrite(BIA, speed);
  analogWrite(BIB, 0);
        break;
      case 'H':
        digitalWrite(AIB, HIGH);
        analogWrite(BIA, 0);
  analogWrite(BIB, speed);
        break;
      case 'J':
        digitalWrite(AIB, HIGH);
        analogWrite(BIA, speed);
  analogWrite(BIB, 0);
        break;
      default:
        digitalWrite(AIA, LOW);
        digitalWrite(AIB, LOW);
        analogWrite(BIA, 0);
  analogWrite(BIB, 0);
        break;
    }

    if(cmd == 'W')
    {
      digitalWrite(JI, HIGH);
      Serial.println("Jiro ok");
    }
   
    if(cmd == 'w')
    {
      digitalWrite(JI, LOW);
    }

    if(cmd == 'V')
    {
      tone(KX, 1000);
    }

    if(cmd == 'v')
    {
      noTone(KX);
    }
  }
}