#include <EasyUltrasonic.h>

#define TRIGPIN 14
#define ECHOPIN 27

EasyUltrasonic ultrasonic;

unsigned long yellowStartTime = 0;
unsigned long blueStartTime = 0;
unsigned long redStartTime = 0;

bool yellowActive = false;
bool blueActive = false;
bool redActive = false;

void setup() {
  Serial.begin(115200);
  pinMode(4, OUTPUT);
  pinMode(16, OUTPUT);
  pinMode(17, OUTPUT);
  ultrasonic.attach(TRIGPIN, ECHOPIN);
  delay(100);
}

void loop() {
  float distanceCM = ultrasonic.getDistanceCM();

  if (distanceCM <= 10 && !yellowActive) {
    yellowStartTime = millis();
    yellowActive = true;
    digitalWrite(4, HIGH);
  }
  if (yellowActive && millis() - yellowStartTime >= 10000) {
    digitalWrite(4, LOW);
    yellowActive = false;
  }

  if (distanceCM <= 20 && !blueActive) {
    blueStartTime = millis();
    blueActive = true;
    digitalWrite(16, HIGH);
  }
  if (blueActive && millis() - blueStartTime >= 10000) {
    digitalWrite(16, LOW);
    blueActive = false;
  }

  if (distanceCM <= 30 && !redActive) {
    redStartTime = millis();
    redActive = true;
    digitalWrite(17, HIGH);
  }
  if (redActive && millis() - redStartTime >= 10000) {
    digitalWrite(17, LOW);
    redActive = false;
  }

  delay(100);
}