Homemade sensored ESC (PWM input code)

/*
 * Electronoobs sensored brushed motor electronic speed controller code
 * Connect the sensors to pins 8, 9 and 10
 * High gates to pins 7, 5 and 3
 * Low gates to 6, 4 and 2
 * More on http://www.electronoobs.com/eng_circuitos_tut19.php
 */

int pot = A3;
int SensorA = 8;
int SensorB = 9;
int SensorC = 10;
int pwm_pin = 11;

//We create variables for the time width value of the PWM input signal
unsigned long counter, current_count;
byte lastPWM_state;
int PWM_width = 1000;

int fase = 1;
int Delay=4000;
unsigned long previousMillis = 0; 
unsigned long currentMillis = 0;

int fase = 1;
int Delay=4000;
unsigned long previousMillis = 0; 
unsigned long currentMillis = 0;

void setup() {
  //Define sensor pins and potentiometer as inputs
  pinMode(pot,INPUT);
  pinMode(SensorA,INPUT);
  pinMode(SensorB,INPUT);
  pinMode(SensorC,INPUT);
  pinMode(pwm_pin,INPUT);


   
  DDRD  |= B11111100;  // Sets D2, D3, D4, D5, D6 and D7 as OUTPUT 
  PORTD &= B00000011;  // D2-D7 LOW
  PCICR |= (1 << PCIE0);    //enable PCMSK0 scan                                                 
  PCMSK0 |= (1 << PCINT0);  //Set pin D8 trigger an interrupt on state change.   sensor A
  PCMSK0 |= (1 << PCINT1);  //Set pin D9 trigger an interrupt on state change.   sensor B
  PCMSK0 |= (1 << PCINT2);  //Set pin D10 trigger an interrupt on state change.  sensor C     
  PCMSK0 |= (1 << PCINT3);  //Set pin D11 trigger an interrupt on state change.  PWM input for speed  
  
  currentMillis = micros();
}


void loop() {

  currentMillis = micros();
  if(currentMillis - previousMillis >= Delay){
  
    previousMillis += Delay;
   
    if(PWM_width > 1070)
    {
      switch(fase){
  
        //Phase1 A-B
        case 1:
        PORTD = B10010000;  //  Pin 7 and 4 to HIGH
        break;       
    
        //Phase2 C-B
        case 2:
        PORTD = B00011000;  //  Pin 3 and 4 to HIGH
        break;
    
        //Phase3 C-A
        case 3:
        PORTD = B01001000;  //  Pin 3 and 6 to HIGH
        break;
     
        //Phase4 B-A
        case 4:
        PORTD = B01100000;  //  Pin 5 and 6 to HIGH
        break;
    
        //Phase5 B-C
        case 5:
        PORTD = B00100100;  //  Pin 5 and 2 to HIGH
        break;
    
        //Phase6 A-C
        case 6:
        PORTD = B10000100;  //  Pin 7 and 2 to HIGH
        break;
      }//end of switch   
    }//End of if 1070    
  }//Case of if millis  

  else
    {
      PORTD = B01010100;  //  Else we stop everything
    }

    Delay=map(PWM_width,1000,1800,3000,10);
                          
}//Void end




ISR(PCINT0_vect){  

  current_count = micros();
  
  if(PINB & B00001000 ){                                                                 
    if(lastPWM_state == 0){                                             
      lastPWM_state = 1;                                                  
      counter = current_count;                                               
    }
  }
  else if(lastPWM_state == 1){                                             
    lastPWM_state = 0;                                                    
    PWM_width = current_count - counter; 
    }

  
  //This part will run any time any of the sensor pins will change its value.
  if(  (PINB & B00000101) && fase == 6  ){   
    fase = 1;    
  }

  if(  (PINB & B00000100) && fase == 1 ){   
    fase = 2;    
  }

  if(  (PINB & B00000110) && fase == 2 ){   
    fase = 3;    
  }

  if(  (PINB & B00000010) && fase == 3 ){   
    fase = 4;    
  }

  if(  (PINB & B00000011) && fase == 4 ){   
    fase = 5;    
  }

  if(  (PINB & B00000001) && fase == 5 ){   
    fase = 6;    
  }
}