Robot that kicks soda cans

// NewPing library is included
#include <NewPing.h> 
// Here I declare what is connected to each pin on the Arduino
int ENA_LEFT = 22;
int IN1_LEFT = 24;
int IN2_LEFT = 26;
int IN3_LEFT = 28;
int IN4_LEFT = 30;
int ENB_LEFT = 32;
int ENA_RIGHT = 40;
int IN1_RIGHT = 42;
int IN2_RIGHT = 44;
int IN3_RIGHT = 46;
int IN4_RIGHT = 48;
int ENB_RIGHT = 50;
int Distance;

int TRIGGER_PIN = 51;
int ECHO_PIN = 53;
int MAX_DISTANCE = 500;
NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE);

// All pins are declared as outputs
// pins of the sensor (TRIGGER AND ECHO) doesn't have to be declared here
void setup() {
  pinMode(ENA_LEFT, OUTPUT);
  pinMode(IN1_LEFT, OUTPUT);
  pinMode(IN2_LEFT, OUTPUT);
  pinMode(IN3_LEFT, OUTPUT);
  pinMode(IN4_LEFT, OUTPUT);
  pinMode(ENB_LEFT, OUTPUT);
  pinMode(ENA_RIGHT, OUTPUT);
  pinMode(IN1_RIGHT, OUTPUT);
  pinMode(IN2_RIGHT, OUTPUT);
  pinMode(IN3_RIGHT, OUTPUT);
  pinMode(IN4_RIGHT, OUTPUT);
  pinMode(ENB_RIGHT, OUTPUT); 

}

void loop() {
  // The sensor measures de distance and stores in a variable called
  // "Distance"
  unsigned int uS = sonar.ping();
  delay(32);
  Distance = sonar.convert_cm(uS);
  
  // If the distance is 57 or more the robot starts rotating in its own axis 
  // 57 is the distance in cm between a soda can and the sensor
  // you can adjust this value if needed
  if ((Distance > 57) or (Distance = 0)){
    turn();
  }
  
  // If the distance is less than 57 cm it moves foward and then backwards
  // 900 is the time in miliseconds the motors stay turned on
  // while moving foward or backwards you can adjust this value if needed
  else{
    turn();
    delay(50);
    stop_();
    foward();
    delay(900);
    stop_();
    delay(400);
    back();
    delay(900);
    stop_();
     
  }
  
}

// functions that are called on voidloop() 
void foward(){
  digitalWrite(ENA_LEFT, HIGH);
  digitalWrite(ENB_LEFT, HIGH);
  digitalWrite(IN1_LEFT, HIGH);
  digitalWrite(IN2_LEFT, LOW);
  digitalWrite(IN3_LEFT, HIGH);
  digitalWrite(IN4_LEFT, LOW);

  digitalWrite(ENA_RIGHT, HIGH);
  digitalWrite(ENB_RIGHT, HIGH);
  digitalWrite(IN1_RIGHT, HIGH);
  digitalWrite(IN2_RIGHT, LOW);
  digitalWrite(IN3_RIGHT, HIGH);
  digitalWrite(IN4_RIGHT, LOW);  
}

void stop_(){
  digitalWrite(ENA_LEFT, LOW);
  digitalWrite(ENB_LEFT, LOW);
  digitalWrite(ENA_RIGHT, LOW);
  digitalWrite(ENB_RIGHT, LOW); 
}

void back(){
  digitalWrite(ENA_LEFT, HIGH);
  digitalWrite(ENB_LEFT, HIGH);
  digitalWrite(IN1_LEFT, LOW);
  digitalWrite(IN2_LEFT, HIGH);
  digitalWrite(IN3_LEFT, LOW);
  digitalWrite(IN4_LEFT, HIGH);

  digitalWrite(ENA_RIGHT, HIGH);
  digitalWrite(ENB_RIGHT, HIGH);
  digitalWrite(IN1_RIGHT, LOW);
  digitalWrite(IN2_RIGHT, HIGH);
  digitalWrite(IN3_RIGHT, LOW);
  digitalWrite(IN4_RIGHT, HIGH);
}

void turn(){
  digitalWrite(ENB_RIGHT, HIGH);
  digitalWrite(ENA_RIGHT, HIGH);
  digitalWrite(IN3_RIGHT, HIGH);
  digitalWrite(IN4_RIGHT, LOW);
  digitalWrite(IN1_RIGHT, HIGH);
  digitalWrite(IN2_RIGHT, LOW);
}