int val=3;
int stop=7;
void setup() {
  pinMode(A0, INPUT);
  attachInterrupt(digitalPinToInterrupt(18),reset,HIGH);
}
void loop() {
  int a=analogRead(A0);
    for (int i=0 ;i<=255;i++){
      analogWrite(val,i);
      delay(a/100+1);
    }
    if (val >= stop) {
    val=1;
    stop --;
    }
    for (int i=255 ;i>=0;i--){
      analogWrite(val,i);
      delay(a/100+1);
    }
    val++;
}


void reset() {
  val=3;
  stop=7;
  analogWrite(7,0);
  analogWrite(6,0);
  analogWrite(5,0);
  analogWrite(4,0);
  analogWrite(3,0);
}