#include <SoftwareSerial.h>

const byte rxPin = 9;
const byte txPin = 10;

// Set up a new SoftwareSerial object
SoftwareSerial mySerial(rxPin, txPin);

int IN1 = 2;
int IN2 = 7;
int IN3 = 4;
int IN4 = 3;
const int LSpeed = 6;
const int RSpeed = 5;
int speedR = 150;  //0-2e55
int speedL = 150;

String str;
int blueToothVal;

#define trigPin 11  //ULTRASONIC input 1
#define echoPin 12  //ULTRASONIC input 2
long duration, distance;

void setup() {
  Serial.begin(9600);
  mySerial.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 {
    bluetooth();
  }
}

void bluetooth() {
  while (mySerial.available())  // Read bluetooth commands over Serial1 // Warning: If an error with Serial1 occurs, make sure Arduino Mega 2560 is Selected
  {
    {
      str = mySerial.readStringUntil('\n');  // str is the temporary variable for storing the last sring sent over bluetooth from Android device
      //Serial.print(str);
    }

    blueToothVal = (str.toInt());  //  convert the string 'str' into an integer and assign it to blueToothVal
Serial.println(blueToothVal);
    switch (blueToothVal) {
      case 1:
        FRONT();
        delay(10);
        break;

      case 2:
        BACKWARDS();
        delay(10);
        break;

      case 3:
        LEFTT();
        delay(10);
        //STOP();
        break;

      case 4:
        RIGHTT();
        delay(10);
        //STOP();
        break;

      case 5:
        STOP();
        break;

    }  // end of switch case

  }  // end of while loop Serial1 read
}

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);
}