int led = 0;
int Time= 5;
void setup() {
// initialize digital pin 13 as an output.
pinMode(13, OUTPUT);
}
// the loop function runs over and over again forever
void loop() {
analogWrite(13, led);
led = led +Time;
if (led == 255 || led == 0){
Time = -Time;
}
delay(30);
}