#define red 22
#define yellow 21
#define green 18
#define blue 5
#define trig 23
#define echo 15
long duration,distance;
void setup() {
  // put your setup code here, to run once:
  pinMode(red,OUTPUT);
  pinMode(yellow,OUTPUT);
  pinMode(green, OUTPUT);
  pinMode(blue, OUTPUT);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
   // this speeds up the simulation
digitalWrite(trig, LOW);
delayMicroseconds(2);
digitalWrite(trig, HIGH);
delayMicroseconds(10);
digitalWrite(trig, LOW);
duration=pulseIn(echo,HIGH);
distance=(duration/2)*0.0343;
delay(5);
if(distance>20&&distance<=80){
  digitalWrite(red, HIGH);
  digitalWrite(yellow, LOW);
  digitalWrite(green, LOW);
  digitalWrite(blue, LOW);
}
if(distance>81&&distance<=140){
  digitalWrite(red, HIGH);
  digitalWrite(yellow, HIGH);
  digitalWrite(green, LOW);
  digitalWrite(blue, LOW);
}
if(distance>141&&distance<=200){
  digitalWrite(red, HIGH);
  digitalWrite(yellow, HIGH);
  digitalWrite(green, HIGH);
  digitalWrite(blue, LOW);
}
if(distance>=201){
  digitalWrite(red, HIGH);
  digitalWrite(yellow, HIGH);
  digitalWrite(green, HIGH);
  digitalWrite(blue, HIGH);
}
}