start & beep

//#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

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);
}
void run(int time)  // 前进
{
  digitalWrite(Right_motor_go, HIGH);  // 右电机前进
  digitalWrite(Right_motor_back, LOW);
  analogWrite(Right_motor_go, 200);  //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, 200);
  delay(time * 100);  //执行时间，可以调整
}

void brake(int time)  //刹车，停车
{
  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)
{
  digitalWrite(Right_motor_go, HIGH);  // 右电机前进
  digitalWrite(Right_motor_back, LOW);
  analogWrite(Right_motor_go, 200);
  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(int time)  //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, 200);
  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, 200);
  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)
{
  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, 200);  //PWM比例0~255调速
  delay(time * 100);                  //执行时间，可以调整
}

void spin_right(int time)  //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, 200);  //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, 200);  //PWM比例0~255调速
  delay(time * 100);                  //执行时间，可以调整
}

void back(int time)  //后退
{
  digitalWrite(Right_motor_go, LOW);  //右轮后退
  digitalWrite(Right_motor_back, HIGH);
  analogWrite(Right_motor_go, 0);
  analogWrite(Right_motor_back, 150);  //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, 150);
  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() {
  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
  back(10);        //后退1s
  brake(5);        //停止0.5s
  run(10);         //前进1s
  brake(5);        //停止0.5s
  left(10);        //向左转1s
  right(10);       //向右转1s
  spin_left(20);   //向左旋转2s
  spin_right(20);  //向右旋转2s
  brake(5);        //停车
}