int trigger_pin = 27;
int echo_pin = 26;
#define red 22
#define blue 19
#define green 18
float d;

void setup() {
  Serial.begin(115200);
  pinMode(trigger_pin, OUTPUT);
  pinMode(echo_pin, INPUT);
  pinMode(red, OUTPUT);
  pinMode(blue, OUTPUT);
  pinMode(green, OUTPUT);
}

int wdistance() {
  digitalWrite(trigger_pin, LOW);
  delay(10);
  digitalWrite(trigger_pin, HIGH);
  delay(100);
  digitalWrite(trigger_pin, LOW);
  d = pulseIn(echo_pin, HIGH);
  return (d * 0.034 / 2) + 1;

  delay(1000);
}

void loop() {
  int distance = wdistance();

  Serial.println(String(distance));
  if (distance > 100) {
    digitalWrite(red, HIGH);
  }
  else {
    digitalWrite(red, LOW);
  }
  if (distance > 200) {
    digitalWrite(blue, HIGH);
  }
  else {
    digitalWrite(blue, LOW);
  }
  if (distance > 300) {
    digitalWrite(green, HIGH);
  }
  else {
    digitalWrite(green, LOW);
  }
  if (distance < 305) {
    digitalWrite(green, LOW);
  }
  else {
    digitalWrite(green, LOW);
  }
  delay(10);
}