Ultrasonic Sensor Interfacing With STM32

const int pingPin = PB10;
const int echoPin = PB1;

const int LED1 = PB0;
const int LED2 = PB5;
const int LED3 = PB6;
const int LED4 = PB7;

void setup() {
  pinMode(LED1 , OUTPUT);
  pinMode(LED2 , OUTPUT);
  pinMode(LED3 , OUTPUT);
  pinMode(LED4 , OUTPUT);
   Serial.begin(115200); // Starting Serial Terminal
}

void loop() {
   long duration, distance;
   pinMode(pingPin, OUTPUT);
   digitalWrite(pingPin, LOW);
   delayMicroseconds(2);
   digitalWrite(pingPin, HIGH);
   delayMicroseconds(10);
   digitalWrite(pingPin, LOW);
   pinMode(echoPin, INPUT);
   duration = pulseIn(echoPin, HIGH);
   Serial.print("Distance from the object = ");
   distance = microsecondsToCentimeters(duration);
   
   Serial.print(distance);
   Serial.print("cm");
   Serial.println();
    if ( distance <= 7 )
  {
    digitalWrite(LED1, HIGH);
  }
  else
  {
    digitalWrite(LED1, LOW);
  }
  if ( distance <= 14 )
  {
    digitalWrite(LED2, HIGH);
  }
  else
  {
    digitalWrite(LED2, LOW);
  }
  if ( distance <= 21 )
  {
    digitalWrite(LED3, HIGH);
  }
  else
  {
    digitalWrite(LED3, LOW);
  }
  if ( distance <= 28 )
  {
    digitalWrite(LED4, HIGH);
  }
  else
  {
    digitalWrite(LED4, LOW);
  }
 
   delay(100);
}

long microsecondsToCentimeters(long microseconds) {
   return microseconds / 29 / 2;
}