arduino 3路PWM输出

输出的功能是：有加速键，减速键，启动停止，按下启动一个点击先启动5秒后第二个电机启动，按下停止后两个电机同时停止。
#include< MsTimer2.h>
#include< EEPROM.h>
#define STOP 255
int key1=1;
int key2=2;
int key3=3;
int key4=4;
int btn_start=2;
int btn_stop=3;
int btn_speedup=4;
int btn_speeddown=7;
int pwm1=5;
int pwm2=6;
int pwm3=9;
int pwm4=10;
byte  speed_;
byte delay_ms;
bool flag_btn1;
void setup()
{
// delay(100);
   pinMode(3,INPUT_PULLUP);
   pinMode(4,INPUT_PULLUP);
   pinMode(2,INPUT_PULLUP);
   pinMode(7,INPUT_PULLUP);
   pinMode(8,INPUT_PULLUP);
   pinMode(12,INPUT_PULLUP);
   pinMode(pwm1,OUTPUT);
   pinMode(pwm2,OUTPUT);
   pinMode(pwm3,OUTPUT);
   pinMode(pwm4,OUTPUT);
   pinMode(9,OUTPUT);//PWM3
   Serial.begin(9600);
   delay_ms=EEPROM.read(1);

   MsTimer2::set((int)delay_ms*100, onTimer); //设置中断，每1000ms进入一次中断服务程序 onTimer()

   //

   //////////////////////////////////////2-启动   3-停止 4-加速  5-减速
   speed_=EEPROM.read(0);
   attachInterrupt( digitalPinToInterrupt(2), start_all, FALLING);
   attachInterrupt( digitalPinToInterrupt(3), stop_all, FALLING);

   analogWrite(5,STOP);
   analogWrite(6,STOP);
   analogWrite(9,STOP);
   Serial.println(speed_);
   Serial.println(delay_ms*100);
   delay(100);

   flag_btn1=false;
}
///////////////////////////全部停止
void speed_up()
{

   if(speed_<=245)
     speed_+=10;
   analogWrite(6,speed_);  
   analogWrite(5,speed_);
   analogWrite(9,speed_);
   delay(100);
   while(!digitalRead(4));
}

void speed_down()
{

   if(speed_>=10)
     speed_-=10;
     else
     speed_=0;
     analogWrite(6,speed_);  
   analogWrite(5,speed_);
   analogWrite(9,speed_);  

   delay(100);
   while(!digitalRead(7));
}
///////////////////////////全部停止
void stop_all()
{

     flag_btn1=false;
   analogWrite(5,STOP);
   analogWrite(6,STOP);
   analogWrite(9,STOP);
   delay(100);
   while(!digitalRead(3));
}
///////////////////////////全部启动
void start_all()
{
   flag_btn1=true;
   analogWrite(5,speed_);
   analogWrite(9,speed_);
   MsTimer2::start();
   delay(100);
   while(!digitalRead(2));
}

void onTimer()
{
   analogWrite(6,speed_);
   MsTimer2::stop();
//  Serial.print("timer ");
//  Serial.println(tick++);
}
void loop()
{
   if(digitalRead(4)==LOW)
   {
       if(speed_<=245)
         speed_=speed_+10;
       else
         speed_=255;
     analogWrite(6,speed_);  
     analogWrite(5,speed_);
     analogWrite(9,speed_);
       EEPROM.write(0, speed_);
       Serial.println(speed_);
       delay(100);
       while(digitalRead(4)==LOW);

   }
   if(digitalRead(7)==LOW)
   {
       if(speed_>=10)
         speed_=speed_-10;
       else
         speed_=0;
       analogWrite(6,speed_);  
     analogWrite(5,speed_);  
     analogWrite(9,speed_);
     EEPROM.write(0, speed_);
       Serial.println(speed_);
     delay(100);
     while(digitalRead(7)==LOW);
   }
if(digitalRead(8)==LOW)
   {
     if(delay_ms<50)
       delay_ms++;
     else
     delay_ms=50;
     MsTimer2::set(delay_ms*100, onTimer);
     EEPROM.write(1, delay_ms);
       Serial.println(delay_ms*100);
     delay(100);
     while(digitalRead(8)==LOW);
   }
if(digitalRead(12)==LOW)
   {
     if(delay_ms>1)
     delay_ms--;
       else
       delay_ms=0;
       MsTimer2::set(delay_ms*100, onTimer);  
     EEPROM.write(1, delay_ms);
     Serial.println(delay_ms*100);
     delay(100);
     while(digitalRead(12)==LOW);
   }
}

sketch_sep21a.cpp: In function 'void loop()':
sketch_sep21a:146: error: 'MsTimer2' has not been declared
sketch_sep21a:158: error: 'MsTimer2' has not been declared

上面两个库是自带的还是需要下载的？