#define PIN_TRIG 26
#define PIN_ECHO 25
#define LOWLED 18
#define MIDLED 19
#define HIGHLED 21
#define MOTOR 27
unsigned int level = 0;

void setup(){
  pinMode(18, OUTPUT);
  pinMode(19, OUTPUT);
  pinMode(21, OUTPUT);
  pinMode(27, OUTPUT);
  digitalWrite(18, HIGH);
  digitalWrite(19, HIGH);
  digitalWrite(21, HIGH);
  digitalWrite(27, LOW);


  Serial.begin(115200);
  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);

}
void loop(){
  

  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);

// read the result:

int duration = pulseIn(PIN_ECHO, HIGH);
Serial.print("Distance in CM:");
Serial.print(duration/ 58);
Serial.print("Distance in inches: ");
Serial.println(duration / 148);

 level = duration/ 58;

 if(level < 10 )
 {
  digitalWrite(18, HIGH);
  digitalWrite(19, LOW);
  digitalWrite(21, LOW);
  digitalWrite(27, HIGH);
 }else if (level <40){
  digitalWrite(18, HIGH);
  digitalWrite(19, HIGH);
  digitalWrite(21, LOW);
  digitalWrite(27, HIGH);
 }else if  (level < 70){
  digitalWrite(18, HIGH);
  digitalWrite(27, HIGH);
  digitalWrite(19, HIGH);
  digitalWrite(21, HIGH);
 }else {
  digitalWrite(18, HIGH);
  digitalWrite(27, HIGH);
  digitalWrite(19, HIGH);
  digitalWrite(21, HIGH);
 }

delay(1000);
}