int brightness = 0;? ? //定義整數(shù)型變量brightness與其初始值，此變量用來表示LED的亮度
int fadeAmount = 5;? ? //定義整數(shù)型變量fadeAmount，此變量用來做亮度變化的增減量
int val = 0;
void setup()? {
Serial.begin(9600);// 設(shè)置串口波特率
pinMode(0, INPUT);// 設(shè)置3號模擬口為輸入端口
pinMode(6, OUTPUT);// 設(shè)置6號數(shù)字口為輸出端口
}
void loop()? {
val = analogRead(0);
Serial.print(val);
Serial.println();
if (val > 20) {
analogWrite(6, brightness);//把brightness的值寫入6號端口
brightness = brightness + fadeAmount;//改變brightness值，使亮度在下一次循環(huán)發(fā)生改變
if (brightness == 0 || brightness == 255) {
fadeAmount = -fadeAmount ; //在亮度最高與最低時進(jìn)行翻轉(zhuǎn)
}
delay(30); //延時30毫秒
}
else
{
digitalWrite(6, HIGH);? // turn the LED on (HIGH is the voltage level)
delay(100);? ? ? ? ? ? ? // wait for a second
digitalWrite(6, LOW);? ? // turn the LED off by making the voltage LOW
delay(100);? ? ? ? ? ? ? // wait for a second
}
}
