PWM点灯プログラム①

int LED_PIN = 12;(ピン番号)
int tim = 0;
int duty = 28;

void setup() {
// put your setup code here, to run once:
Serial.begin(9800);
pinMode( LED_PIN, OUTPUT );
}
void loop() {
for(;;){
tim = 0;
// put your main code here, to run repeatedly:
for(int i = 0;i < duty ; i++){ //徐々に点灯
digitalWrite( LED_PIN, HIGH );
delay(tim);
digitalWrite( LED_PIN, LOW );
delay(duty - tim);
tim += 1;
}
digitalWrite( LED_PIN, HIGH );
delay(1000);
tim = 0;
for(int i = 0;i < duty ; i++){ //徐々に点灯
digitalWrite( LED_PIN, HIGH );
delay(duty - tim);
digitalWrite( LED_PIN, LOW );
delay(tim);
tim += 1;
}
digitalWrite( LED_PIN, LOW );
delay(1000);
}
}