Cleaner Bot

#define enA 9
#define enB 10
#define in1 8
#define in2 7
#define in3 6
#define in4 5
#define rly 2

//infared pins
#define lftIr 12
#define ctrIr 4
#define rghIr 3

String msg="";
int spd=150;
bool swtch=0;

void setup() {
  // put your setup code here, to run once:
  pinMode(enA, OUTPUT);
  pinMode(enB, OUTPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);
  pinMode(rly, OUTPUT);
  
  Serial.begin(38400);
}

void loop() {
  // put your main code here, to run repeatedly:
  if(Serial.available()){
    msg=Serial.readString();
  }

  if (msg=="start cleaning"){
    swtch=1;
  }
  else if(msg=="stop cleaning"){
    swtch=0;
  }
  if (swtch==1) {
    moveBot();
    digitalWrite(rly,HIGH);
  }
  else{
    digitalWrite(rly,LOW);
    stopAll();
    }
}

void moveBot(){
  //delay(500);
 // stopAll();
  //delay(2000);
  analogWrite(enA, 100);
  analogWrite(enB, 100);
  int leftIr=digitalRead(lftIr);
   int centerIr=digitalRead(ctrIr);
   int rightIr=digitalRead(rghIr);
  

   if (leftIr==LOW && rightIr==HIGH){
        while(leftIr==LOW){
          rightMov();
          leftIr=digitalRead(lftIr);
        }
        stopAll();
       }
       else if (leftIr==HIGH && rightIr==LOW){
        stopAll();
          while(rightIr==LOW){
            leftMov();
            rightIr=digitalRead(rghIr);
          }
        stopAll(); 
      }
      else if (leftIr==LOW && centerIr==LOW && rightIr==LOW){
          stopAll();
              while(leftIr==LOW || centerIr==LOW || rightIr==LOW){
                backMov();
                leftIr=digitalRead(lftIr);
                centerIr=digitalRead(ctrIr);
                rightIr=digitalRead(rghIr);
                }
                stopAll();
          }
          
      else if (leftIr==HIGH && centerIr==LOW && rightIr==HIGH){
          stopAll();
          while(centerIr==LOW){
            backMov();
            centerIr=digitalRead(ctrIr);
          }
          stopAll();
          delay(10);
          leftMov();
          delay(500);
          stopAll();
        }
      else{
        fowardMov();
        
      }
  }
void fowardMov(){
  digitalWrite(in2,HIGH);
  digitalWrite(in4,HIGH);
  digitalWrite(in1, LOW);
  digitalWrite(in3, LOW);
}

void backMov(){
  digitalWrite(in1,HIGH);
  digitalWrite(in3,HIGH);
  digitalWrite(in2, LOW);
  digitalWrite(in4, LOW);
}

void rightMov(){
  digitalWrite(in1, HIGH);
  digitalWrite(in4, HIGH);
  digitalWrite(in2, LOW);
  digitalWrite(in3, LOW);
}

void leftMov(){
  digitalWrite(in2, HIGH);
  digitalWrite(in3, HIGH);
  digitalWrite(in1, LOW);
  digitalWrite(in4, LOW);
}

void stopAll(){
  digitalWrite(in1, LOW);
  digitalWrite(in2, LOW);
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);
}