Page 311 - 최강 아두이노 퍼스트 참고서

digitalWrite(ledPin, LOW); // turn LED OFF playTone(0, 0);
delay(300); if (pirState == HIGH){ // we have just turned off
Serial.println("Motion ended!");
// We only want to print on the output change, not state pirState = LOW;
}
}
}
// duration in mSecs, frequency in hertz void playTone(long duration,
int freq) { duration *= 1000;
int period = (1.0 / freq) * 1000000; long elapsed_time = 0;
while (elapsed_time < duration)
{ digitalWrite(pinSpeaker,HIGH);
delayMicroseconds(period / 2); digitalWrite(pinSpeaker,
LOW); delayMicroseconds(period / 2); elapsed_time +=
(period);
}
}

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