int IN1 = 2;
int IN2 = 3;
int IN3 = 4;
int IN4 = 5;
const int LSpeed = 10;
const int RSpeed = 9;
int speedR = 150;  //0-255
int speedL = 150;

String str;
int blueToothVal;

#define trigPin A0
#define echoPin A1
long duration, distance;

void setup() {
  Serial.begin(9600);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
  pinMode(LSpeed, OUTPUT);
  pinMode(RSpeed, OUTPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
}


void loop() {
  analogWrite(LSpeed, speedL);
  analogWrite(RSpeed, speedR);
  delay(50);

  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  distance = duration * 0.034 / 2;
  Serial.println(distance);
  delay(10);

  if (distance <= 30) {
    STOP();
    delay(300);
    BACKWARDS();
    delay(400);
    STOP();
    delay(300);
    RIGHTT();
    delay(700);
    STOP();
  }

  else {
    FRONT();
  }
}

void STOP() {
  digitalWrite(IN1, 0);
  digitalWrite(IN2, 0);

  digitalWrite(IN3, 0);
  digitalWrite(IN4, 0);
}

void FRONT() {
  digitalWrite(IN1, 0);
  digitalWrite(IN2, 1);

  digitalWrite(IN3, 0);
  digitalWrite(IN4, 1);
}

void BACKWARDS() {
  digitalWrite(IN1, 1);
  digitalWrite(IN2, 0);

  digitalWrite(IN3, 1);
  digitalWrite(IN4, 0);
}

void RIGHTT() {

  //delay(100);
  digitalWrite(IN1, 0);
  digitalWrite(IN2, 1);

  digitalWrite(IN3, 1);
  digitalWrite(IN4, 0);
}

void LEFTT() {

  //delay(100);
  digitalWrite(IN1, 1);
  digitalWrite(IN2, 0);

  digitalWrite(IN3, 0);
  digitalWrite(IN4, 1);
}