#include <AccelStepper.h>

#define STEP_PIN 8
#define DIR_PIN 9
#define TRIG_PIN A1
#define ECHO_PIN A2

AccelStepper stepper(AccelStepper::DRIVER, STEP_PIN, DIR_PIN);

void setup() {
  Serial.begin(9600); // Initialize Serial communication
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  stepper.setMaxSpeed(10000); // Set maximum speed
  stepper.setAcceleration(5000); // Set acceleration
}

void loop() {
  long distance = measureDistance();

  // Print the distance to the Serial Monitor
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.println(" cm");

  if (distance > 20) {
    stepper.moveTo(200); // Move to position 200 steps forward
  } else {
    stepper.moveTo(0); // Move to position 0 steps (backward)
  }

  // Run the stepper until it reaches the target position
  stepper.run();
}

long measureDistance() {
  digitalWrite(TRIG_PIN, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  long duration = pulseIn(ECHO_PIN, HIGH);
  long distance = (duration * 0.0034) / 2; // Calculate distance in cm
  return distance;
}