我得到一个错误，如果不在范围内
int亮度= 120; //开始时多少LED会亮
int fadeAmount = 10;
unsigned long currentTime；
无符号长loopTime;
const int pin_A = 19; //初始化编码器引脚A的引脚19
const int pin_B = 18; //初始化编码器引脚B的引脚18
int按钮= 28; //初始化按钮的插针28。
无符号字符编码器_A;
无符号字符编码器_B;
无符号字符编码器_A_prev = 0;
无效设置（）{
pinMode（3，输出）; //将引脚3声明为led的输出
pinMode（pin_A，INPUT）; //将引脚19声明为输入
pinMode（pin_B，INPUT）; //将引脚18声明为输入
currentTime = millis（）;
loopTime = currentTime;
}
无效循环（）{
currentTime = millis（）; //此命令将获取当前经过的时间
if（currentTime> =（loopTime + 5））{//距离编码器最后一次检查5毫秒= 200Hz
encoder_A = digitalRead ( pin_A ) ; // Reading the encoder pins
encoder_B = digitalRead ( pin_B ) ; // Reading the encoder pins
if ( ( !encoder_A ) && ( encoder_A_prev ) ) {
// A has gone from high to low
If ( encoder_B ) { // encoder is moved clock wised so B is high
If ( brightness + fadeAmount <= 255 ) brightness += fadeAmount ; // This command will increase the brightness
}
else {
// if encoder is moved counter-clockwise then b will be low
If( brightness - fadeAmount >= 0 ) brightness -= fadeAmount ; // This will decrease the brightness
}
}
encoder_A_prev = encoder_A ; // this will Store value of A for next time
analogWrite ( 3, brightness ) ; // This will set the brightness of pin 3:
loopTime = currentTime ;
}
}