#include <TM1637.h> 

#define trigPin 2  
#define echoPin 4  
#define clockPin 5 
#define dataPin 18 

const int digits[] = {0x3F, 0x06, 0x5B, 0x4F, 0x66, 0x6D, 0x7D, 0x07, 0x7F, 0x6F}; 

long duration; 
int distance;  

TM1637 display(clockPin, dataPin); 

void setup() {
  pinMode(trigPin, OUTPUT);  
  pinMode(echoPin, INPUT);  

  Serial.begin(115200);      
  display.init();           
  display.setBrightness(10); 
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  duration = pulseIn(echoPin, HIGH);

  distance = duration * 0.034 / 2;

  // Print the distance to the serial monitor
  Serial.print("Distance: ");
  Serial.println(distance);

  // Display the distance on the seven-segment display
  int digit1 = distance / 10; // Extract the tens digit
  int digit2 = distance % 10;  // Extract the units digit

  // Determine which digit to blink based on the distance range
  int blinkDigit = -1;
  if (distance >= 0 && distance <= 40) {
    blinkDigit = 0;
  } else if (distance >= 41 && distance <= 80) {
    blinkDigit = 1;
  } else if (distance >= 81 && distance <= 120) {
    blinkDigit = 2;
  } else if (distance >= 121 && distance <= 160) {
    blinkDigit = 3;
  } else if (distance >= 161 && distance <= 200) {
    blinkDigit = 4;
  } else if (distance >= 201 && distance <= 240) {
    blinkDigit = 5;
  } else if (distance >= 241 && distance <= 280) {
    blinkDigit = 6;
  } else if (distance >= 281 && distance <= 320) {
    blinkDigit = 7;
  } else if (distance >= 321 && distance <= 360) {
    blinkDigit = 8;
  } else if (distance >= 361 && distance <= 400) {
    blinkDigit = 9;
  }

  if (blinkDigit != -1) {
    // Blink the selected digit
    for (int i = 0; i < 5; i++) {
      display.display(digits[blinkDigit]);
      delay(250);
      display.display(0x00); // Turn off the digit
      delay(250);
    }
  } else {
    // Display the distance normally if it doesn't fall into any range
    display.display(digits[digit1] << 8 | digits[digit2]); 
  }

  delay(100);
}