//============================智宇科技===========================
//  智能小车黑线循迹实验
//===============================================================
//#include <Servo.h> 
int Left_motor_go=8;     //左电机前进(IN1)
int Left_motor_back=9;     //左电机后退(IN2)
int Right_motor_go=10;    // 右电机前进(IN3)
int Right_motor_back=11;    // 右电机后退(IN4)

int key=A2;//定义按键 数字A2 接口
int beep=A3;//定义蜂鸣器 数字A3 接口

const int SensorRight = 3;   	//右循迹红外传感器(P3.2 OUT1)
const int SensorLeft = 4;     	//左循迹红外传感器(P3.3 OUT2)

int SL;    //左循迹红外传感器状态
int SR;    //右循迹红外传感器状态

void setup()
{
  //初始化电机驱动IO为输出方式
  pinMode(Left_motor_go,OUTPUT); // PIN 8 (PWM)
  pinMode(Left_motor_back,OUTPUT); // PIN 9 (PWM)
  pinMode(Right_motor_go,OUTPUT);// PIN 10 (PWM) 
  pinMode(Right_motor_back,OUTPUT);// PIN 11 (PWM)
  pinMode(key,INPUT);//定义按键接口为输入接口
  pinMode(beep,OUTPUT);
  pinMode(SensorRight, INPUT); //定义右循迹红外传感器为输入
  pinMode(SensorLeft, INPUT); //定义左循迹红外传感器为输入
}

//=======================智能小车的基本动作=========================
//void run(int time)     // 前进
void run()
{
   digitalWrite(Right_motor_go,HIGH);  // 右电机前进
  digitalWrite(Right_motor_back,LOW);     
  analogWrite(Right_motor_go,60);//PWM比例0~255调速，左右轮差异略增减
  analogWrite(Right_motor_back,0);
  digitalWrite(Left_motor_go,LOW);  // 左电机前进
  digitalWrite(Left_motor_back,HIGH);
  analogWrite(Left_motor_go,0);//PWM比例0~255调速，左右轮差异略增减
  analogWrite(Left_motor_back,60);
  //delay(time * 100);   //执行时间，可以调整  
}

//void brake(int time)  //刹车，停车
void brake()
{
  digitalWrite(Right_motor_go,LOW);
  digitalWrite(Right_motor_back,LOW);
  digitalWrite(Left_motor_go,LOW);
  digitalWrite(Left_motor_back,LOW);
  //delay(time * 100);//执行时间，可以调整  
}

//void left(int time)         //左转(左轮不动，右轮前进)
void left()
{
  digitalWrite(Right_motor_go,HIGH);	// 右电机前进
  digitalWrite(Right_motor_back,LOW);
  analogWrite(Right_motor_go,60); 
  analogWrite(Right_motor_back,0);//PWM比例0~255调速
  digitalWrite(Left_motor_go,LOW);   //左轮后退
  digitalWrite(Left_motor_back,LOW);
  analogWrite(Left_motor_go,0); 
  analogWrite(Left_motor_back,0);//PWM比例0~255调速
  //delay(time * 100);	//执行时间，可以调整  
}

void spin_left()         //左转(左轮后退，右轮前进)
{
   digitalWrite(Right_motor_go,HIGH);	// 右电机前进
  digitalWrite(Right_motor_back,LOW);
  analogWrite(Right_motor_go,60); 
  analogWrite(Right_motor_back,0);//PWM比例0~255调速
  digitalWrite(Left_motor_go,HIGH);   //左轮后退
  digitalWrite(Left_motor_back,LOW);
  analogWrite(Left_motor_go,30); 
  analogWrite(Left_motor_back,0);//PWM比例0~255调速
  //delay(time * 100);	//执行时间，可以调整  
}

//void right(int time)        //右转(右轮不动，左轮前进)
void right()
{
  digitalWrite(Right_motor_go,LOW);   //右电机后退
  digitalWrite(Right_motor_back,LOW);
  analogWrite(Right_motor_go,0); 
  analogWrite(Right_motor_back,0);//PWM比例0~255调速
  digitalWrite(Left_motor_go,LOW);//左电机前进
  digitalWrite(Left_motor_back,HIGH);
  analogWrite(Left_motor_go,0); 
  analogWrite(Left_motor_back,60);//PWM比例0~255调速
  //delay(time * 100);	//执行时间，可以调整  
}

void spin_right()        //右转(右轮后退，左轮前进)
{
  digitalWrite(Right_motor_go,LOW);   //右电机后退
  digitalWrite(Right_motor_back,HIGH);
  analogWrite(Right_motor_go,0); 
  analogWrite(Right_motor_back,30);//PWM比例0~255调速
  digitalWrite(Left_motor_go,LOW);//左电机前进
  digitalWrite(Left_motor_back,HIGH);
  analogWrite(Left_motor_go,0); 
  analogWrite(Left_motor_back,60);//PWM比例0~255调速
  //delay(time * 100);	//执行时间，可以调整    
}

//void back(int time)          //后退
void back(int time)
{
  digitalWrite(Right_motor_go,LOW);  //右轮后退
  digitalWrite(Right_motor_back,HIGH);
  analogWrite(Right_motor_go,0);
  analogWrite(Right_motor_back,60);//PWM比例0~255调速
  digitalWrite(Left_motor_go,HIGH);  //左轮后退
  digitalWrite(Left_motor_back,LOW);
  analogWrite(Left_motor_go,60);
  analogWrite(Left_motor_back,0);//PWM比例0~255调速
  delay(time * 100);     //执行时间，可以调整  
}
//==========================================================

void keysacn()//按键扫描
{
  int val;
  val=digitalRead(key);//读取数字7 口电平值赋给val
  while(!digitalRead(key))//当按键没被按下时，一直循环
  {
    val=digitalRead(key);//此句可省略，可让循环跑空
  }
  while(digitalRead(key))//当按键被按下时
  {
    delay(10);	//延时10ms
    val=digitalRead(key);//读取数字7 口电平值赋给val
    if(val==HIGH)  //第二次判断按键是否被按下
    {
      digitalWrite(beep,HIGH);		//蜂鸣器响
      while(!digitalRead(key))	//判断按键是否被松开
        digitalWrite(beep,LOW);		//蜂鸣器停止
    }
    else
      digitalWrite(beep,LOW);//蜂鸣器停止
  }
}

void loop()
{ 
  keysacn();//调用按键扫描函数  
  while(1)
  {
  //有信号为LOW  没有信号为HIGH   检测到黑线  输出高  检测到白色区域输出低
  SR = digitalRead(SensorRight);//有信号表明在白色区域，车子底板上L1亮；没信号表明压在黑线上，车子底板上L1灭
  SL = digitalRead(SensorLeft);//有信号表明在白色区域，车子底板上L2亮；没信号表明压在黑线上，车子底板上L2灭
  if (SL == LOW&&SR==LOW)
    run();   //调用前进函数
  else if (SL == HIGH & SR == LOW)// 左循迹红外传感器,检测到信号，车子向右偏离轨道，向左转 
    spin_left();
  else if (SR == HIGH & SL == LOW) // 右循迹红外传感器,检测到信号，车子向左偏离轨道，向右转  
    spin_right();
  else // 都是黑色, 停止
  brake();
  }
}