int leftMotor1 =8;
int leftMotor2 =7;
int rightMotor1 =2;
int rightMotor2 =4;
int leftPWM=6;
int rightPWM=5;

int trac1 = 10; //从车头方向的最右边开始排序
int trac2 = 11;
int trac3 = 12;
int trac4 = 13;
int LeftValue1;
int LeftValue2;
int RightValue1;
int RightValue2;
void setup() {

  Serial.begin(9600);
  //测速引脚初始化
  pinMode(leftMotor1, OUTPUT);
  pinMode(leftMotor2, OUTPUT);
  pinMode(rightMotor1, OUTPUT);
  pinMode(rightMotor2, OUTPUT);
  pinMode(leftPWM,OUTPUT);
  pinMode(rightPWM,OUTPUT);
  //寻迹模块D0引脚初始化
  pinMode(trac1, INPUT);
  pinMode(trac2, INPUT);
  pinMode(trac3, INPUT);
  pinMode(trac4, INPUT);
}
void run(int left_speed, int right_speed)
{
  //左电机前进
  digitalWrite(leftMotor1, HIGH);   //左电机前进使能
  digitalWrite(leftMotor2, LOW);  //左电机后退禁止
  analogWrite(leftPWM,left_speed);
  //右电机前进
  digitalWrite(rightMotor1, HIGH);  //右电机前进使能
  digitalWrite(rightMotor2, LOW); //右电机后退禁止
  analogWrite(rightPWM,right_speed);
  }
 void brake(int time)
{
  digitalWrite(leftMotor1, LOW);
  digitalWrite(leftMotor2, LOW);
  digitalWrite(rightMotor1, LOW);
  digitalWrite(rightMotor2, LOW);

  delay(time * 50);
}
void left(int left_speed, int right_speed)
{
  //左电机停止
  digitalWrite(leftMotor1, LOW);    //左电机前进禁止
  digitalWrite(leftMotor2, LOW);  //左电机后退禁止
  analogWrite(leftPWM, left_speed);

  //右电机前进
  digitalWrite(rightMotor1, HIGH);  //右电机前进使能
  digitalWrite(rightMotor2, LOW); //右电机后退禁止
  analogWrite(rightPWM, right_speed);
}
void right(int left_speed, int right_speed)
{
  //左电机前进
  digitalWrite(leftMotor1, HIGH);   //左电机前进使能
  digitalWrite(leftMotor2, LOW);  //左电机后退禁止
  analogWrite(leftPWM, left_speed);

  //右电机停止
  digitalWrite(rightMotor1, LOW);   //右电机前进禁止
  digitalWrite(rightMotor2, LOW); //右电机后退禁止
  analogWrite(rightPWM, right_speed);
}
 //检测到黑线时循迹模块相应的指示灯亮，端口电平为LOW
  //未检测到黑线时循迹模块相应的指示灯灭，端口电平为HIGH
void loop()
{
  LeftValue1  = digitalRead(trac1);
  LeftValue2  = digitalRead(trac2);
  RightValue1 = digitalRead(trac3);
  RightValue2 = digitalRead(trac4);
if(LeftValue1 == HIGH && LeftValue2 ==HIGH && RightValue1 == HIGH && RightValue1 == HIGH)//1 1 1 1
  {
    run(120, 120);
    }
    else if(LeftValue1 == LOW && LeftValue2 ==LOW && RightValue1 == LOW && RightValue1 == LOW)//0 0 0 0
    {
      run(100,100);
    }
    else if(LeftValue1 == HIGH && LeftValue2 ==HIGH && RightValue1 == LOW && RightValue1 == HIGH)//1 1 0 1
    {
      right(50,30);
      }
      else if(LeftValue1 == HIGH && LeftValue2 ==HIGH && RightValue1 == LOW && RightValue1 == LOW)//1 1 0 0
      {
        right(30,0);
        delay(50);
      }
}