int i=0;
void setup() {
  // put your setup code here, to run once:
  pinMode(5, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
 for(i=0; i <= 255; i++){
    analogWrite(5, i);
    analogWrite(5,255-i);
    delay(25);
  }
  for(i=255; i>=0 ; i--){
    analogWrite(8,i);
    analogWrite(5,255-i);
    delay(25);
  }
}