int led1=3;
int led2=11;
int led3=5;
int led4=6;
int led5=10;
int fa=A0;
int hui=A1;
int fmq=8;
int max_sy;
int small_sy;
int zhi;
float cm;
void setup() {
 Serial.begin(9600);
 pinMode(fa,OUTPUT);     
  pinMode(hui,INPUT); 
}

void loop() {
 
    digitalWrite(fa,LOW);   
  delayMicroseconds(2);         
  digitalWrite(fa,HIGH);   
  delayMicroseconds(10);
  digitalWrite(fa,LOW);
  cm = float(pulseIn(hui,HIGH) * 17)/1000; 
 
  Serial.print(cm);                   
  Serial.print("cm");                 
  Serial.println();                   
             

  if(cm>=30){ 
    analogWrite(led1,HIGH);
    analogWrite(led2,HIGH);
    analogWrite(led3,HIGH);
    analogWrite(led4,HIGH);
    analogWrite(led5,HIGH);
  }
    if(cm>=25&&cm<30){ 
    analogWrite(led1,HIGH);
    analogWrite(led2,HIGH);
    analogWrite(led3,HIGH);
    analogWrite(led4,HIGH);
    analogWrite(led5,LOW);
  }
   if(cm>=20&& cm<25){ 
    analogWrite(led1,HIGH);
    analogWrite(led2,HIGH);
    analogWrite(led3,HIGH);
    analogWrite(led4,LOW);
    analogWrite(led5,LOW);
  }
    if(cm>=15&&cm<20){ 
    analogWrite(led1,HIGH);
    analogWrite(led2,HIGH);
    analogWrite(led3,LOW);
    analogWrite(led4,LOW);
    analogWrite(led5,LOW);
  }
    if(cm>=10&&cm<15){ 
    analogWrite(led1,HIGH);
    analogWrite(led2,LOW);
    analogWrite(led3,LOW);
    analogWrite(led4,LOW);
    analogWrite(led5,LOW);
  }
  if(cm>=0&&cm<10){ 
    analogWrite(led1,LOW);
    analogWrite(led2,LOW);
    analogWrite(led3,LOW);
    analogWrite(led4,LOW);
    analogWrite(led5,LOW);
  }
 
 delay(100);


}