/*
digitalwrite  設定的狀態只有兩種高電位雨低電位
analogWrite   則可以控制百分比輸出範圍在0~255
*/

void setup() {
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
}

void ledon(){
  for (int pm = 10; pm < 13; pm++) {
    for (int led = 0; led < 255; led++) {
      analogWrite(pm, led);
      delay(1);
    }
    delay(100);
  }
}

void ledoff(){
  for (int pm = 13; pm >= 10 ; pm--) {
    for (int led = 255; led >= 0; led--) {
      analogWrite(pm, led);
      delay(1);
    }
    delay(100);
  }
}

void loop() {
  ledon();
  ledoff();
  delay(1000);
}