#define TRIG_PIN 9 
#define ECHO_PIN 10
const int led_red=07,led_orange=06,led_yellow=05,led_green=04;

float distance_cm,distance_M;

void setup(){
  pinMode(TRIG_PIN, OUTPUT);
  pinMode(ECHO_PIN, INPUT);
  pinMode(led_red, OUTPUT);
  pinMode(led_orange, OUTPUT);
  pinMode(led_yellow, OUTPUT);
  pinMode(led_green, OUTPUT);
}
void loop(){
  ultrasonicMeasure();
  if(distance_M>=1.00){
    digitalWrite(led_red,HIGH);
  }
  else{
    digitalWrite(led_red,LOW);
  }
  }
float ultrasonicMeasure(){
 digitalWrite (TRIG_PIN, HIGH);
 delayMicroseconds(10);
 digitalWrite (TRIG_PIN, LOW);

 float duration_us= pulseIn(ECHO_PIN,HIGH);
 distance_cm=0.0171 * duration_us;
 distance_M=distance_cm/100;

}