（時間倉促，未精調，只是實現功能）供大家參考：

先定義各接口

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int lled = 7;
int rled = 4;
int lmotor = 19;
int rmotor = 18;
int rdate = 0;
int ldate = 0;
int ledpin = 14;
int l = 0;
int r = 0;
int a = 0;
int b = 0;
int c = 0;
int e = 0;
void setup()
{
 pinMode(lled,INPUT);
 pinMode(rled,INPUT);
 pinMode(lmotor,OUTPUT);
 pinMode(rmotor,OUTPUT);
 pinMode(ledpin,OUTPUT);
}
void run()
{
   for(int i = 0;i < a;i ++)
   {
     digitalWrite(lmotor,HIGH);
     delayMicroseconds(ldate);
     digitalWrite(lmotor,LOW);
     digitalWrite(rmotor,HIGH);
     delayMicroseconds(rdate);
     digitalWrite(rmotor,LOW);
     delay(18);
   }
}
void loop()
{
 l = digitalRead(lled);
 r = digitalRead(rled);
 if ((l == HIGH) || (r == HIGH))
   digitalWrite(ledpin,HIGH);
 else
   digitalWrite(ledpin,LOW);
 if((l == HIGH)&&(r == HIGH))
 {
   while((l == HIGH)&&(r == HIGH))
     {
       l = digitalRead(lled);
       r = digitalRead(rled);
     }
 }
 else if(l == HIGH) //左邊兒檢測到黑線，左轉
 {
   ldate = 1480;
   rdate = 1630;
   a = 10;

 }
 else if(r == HIGH) //右邊兒檢測到黑線，右轉
 {
     ldate = 1350;
     rdate = 1500;
     a = 10;

 }
 else
 {
   ldate = 1300;
   rdate = 1730;
   a = 1;
 }

   run();
}

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上圖若干：

這個小車不算完，因為有太多的功能可供大家玩，比如我就裝上了超聲波和紅外傳感器，是不是挺萌的！

與其叫這個東西小車，不如說它是每個機器人愛好者入門的神車吧！

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