#include "pitches.h"

const byte trigPin = 3;  // pin "trig" branchée à la broche 5 de l'ATTiny85
const byte echoPin = 5;  //pin "echo" branchée à la broche 6 de l'ATTiny85
const byte DISTANCE_max=50;
const byte Vout=6;
byte volt_pwm=0;
byte volt_pwm1=0;
unsigned long t_millis=0;

void setup() {
  pinMode(echoPin, INPUT);
  pinMode(trigPin, OUTPUT);
  pinMode(8, OUTPUT);
  digitalWrite(trigPin, LOW);
  Serial.begin(9600);
}

void loop()
{
  long temps, distance;
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);

  temps = pulseIn(echoPin, HIGH);
  distance = temps * 340/(2*10000);
  Serial.println(distance);

  if(distance<=DISTANCE_max)
  {
  volt_pwm = map(distance, 0, DISTANCE_max, 170, 0);
  analogWrite(Vout,volt_pwm);
  if(millis()>t_millis+(800-pow(volt_pwm1,1.3)))
  {
   Serial.println(pow(volt_pwm1,1.3));
   tone(8,1000+volt_pwm1*3,50);
   t_millis=millis();
   volt_pwm1=volt_pwm;
  }

  }

else
 analogWrite(Vout,0);
 delay(100);
}