const int trigP = 5;
const int echoP = 17;
long duration;
int distance;
int freq;
void setup() {
  // put your setup code here, to run once:
  pinMode(trigP, OUTPUT);
  pinMode(echoP, INPUT);
  Serial.begin(9600);
  pinMode(4, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(trigP, LOW);
  delayMicroseconds(2);
  digitalWrite(trigP, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigP, LOW);
  duration = pulseIn(echoP,HIGH);
  distance = duration*0.034/2;
  Serial.println(distance);
  freq= map(distance,2,400,1023,0);
  analogWrite(4,freq);

}









































// const int trigP = D2;
// const int echoP = D3;
// long duration;
// int distance;
// int freq;
// void setup() {
//   // put your setup code here, to run once:
//   pinMode(trigP, OUTPUT);
//   pinMode(echoP, INPUT);
//   Serial.begin(9600);
//   pinMode(D4, OUTPUT);
// }

// void loop() {
//   // put your main code here, to run repeatedly:
//   digitalWrite(trigP, LOW);
//   delayMicroseconds(2);
//   digitalWrite(trigP, HIGH);
//   delayMicroseconds(10);
//   digitalWrite(trigP, LOW);
//   duration = pulseIn(echoP,HIGH);
//   distance = duration*0.034/2;
//   freq= map(distance,2,400,1023,0);
//   analogWrite(D4,freq);

// }



































  // if (distance < 100 ){
  //   analogWrite(4,freq);
  // }
  // else if( distance <200){
  //   analogWrite(4,100);
  // }
  // else if (distance <350){
  //   analogWrite(4,50);
  // }
  // Serial.print(" Distance:  ");
  // Serial.print(distance);
  // Serial.print(" cm. \n");
  // delay(1000);