#define LED_BUILTIN 16
#define LED_RED 33
#define LED_YELLOW 25
#define LED_GREEN 26
#define LED_WHITE 27

#define TRIG 32
#define ECHO 35

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(LED_RED, OUTPUT);
  pinMode(LED_YELLOW, OUTPUT);
  pinMode(LED_GREEN, OUTPUT);
  pinMode(LED_WHITE, OUTPUT);

  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:

  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  int duration = pulseIn(ECHO, HIGH);
  int distance = duration / 58; // Distance in cm

  String output = "Distance in cm: ";
  output.concat(distance);
 
  if (distance <= 100) {
    digitalWrite(LED_RED, HIGH);
    Serial.println(output);
  } else if (distance > 100 && distance <= 150) {
    digitalWrite(LED_YELLOW, HIGH);
    Serial.println(output);
  } else if (distance > 150 && distance <= 200) {
    digitalWrite(LED_GREEN, HIGH);
    Serial.println(output);
  } else {
    digitalWrite(LED_WHITE, HIGH);
    Serial.println(output);
  }

  digitalWrite(LED_BUILTIN, LOW);
  digitalWrite(LED_RED, LOW);
  digitalWrite(LED_YELLOW, LOW);
  digitalWrite(LED_GREEN, LOW);
  digitalWrite(LED_WHITE, LOW);
}