const int trigPin = 3;  // Trigger pin of HC-SR04 connected to RP2040 GPIO 3
const int echoPin = 4;  // Echo pin of HC-SR04 connected to RP2040 GPIO 4

void setup() {
  Serial.begin(9600);  // Initialize serial communication
  pinMode(trigPin, OUTPUT); // Set trigPin as an OUTPUT
  pinMode(echoPin, INPUT);  // Set echoPin as an INPUT
}

void loop() {
  // Triggering the ultrasonic sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  // Measuring the pulse duration from echoPin
  long duration = pulseIn(echoPin, HIGH);

  // Calculating distance in cm
  float distance_cm = duration * 0.034 / 2;

  // Displaying the distance in Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance_cm);
  Serial.println(" cm");

  delay(1000);  // Delay for 1 second before next measurement
}