#define ECHO_PIN_1 2
#define TRIG_PIN_1 3
#define LED_PIN_1 8
#define ECHO_PIN_2 4
#define TRIG_PIN_2 5
#define LED_PIN_2 13

void setup() 
{
  Serial.begin(115200); 
  pinMode(TRIG_PIN_1, OUTPUT);
  pinMode(ECHO_PIN_1, INPUT);
  pinMode(LED_PIN_1, OUTPUT);
  pinMode(TRIG_PIN_2, OUTPUT);
  pinMode(ECHO_PIN_2, INPUT);
  pinMode(LED_PIN_2, OUTPUT);
}

float readDistanceCM_1() 
{
  digitalWrite(TRIG_PIN_1, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN_1, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN_1, LOW);
  int duration = pulseIn(ECHO_PIN_1, HIGH);
  return duration * 0.034 / 2;
}

float readDistanceCM_2() 
{
  digitalWrite(TRIG_PIN_2, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG_PIN_2, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN_2, LOW);
  int duration = pulseIn(ECHO_PIN_2, HIGH);
  return duration * 0.034 / 2;
}

void loop() 
{
  float distance_1 = readDistanceCM_1();
  float distance_2 = readDistanceCM_2();
  Serial.print("Measured distance 1: ");
  Serial.println(readDistanceCM_1());
  Serial.print("Measured distance 2: ");
  Serial.println(readDistanceCM_2());
  if (distance_1 >= 100)
  {
    digitalWrite(LED_PIN_1, HIGH);
  }
  else
  {
    digitalWrite(LED_PIN_1, LOW);
  }
  if (distance_2 >= 400)
  {
    digitalWrite(LED_PIN_2, HIGH);
  }
  else
  {
    digitalWrite(LED_PIN_2, LOW);
  }
  delay(100);
}