• 同等地位的N個(gè)任務(wù)
• 每個(gè)任務(wù)有固定的執(zhí)行間隔

• 典型的Arduino模式

  
  
  setup-loop

• 將loop進(jìn)行中的任務(wù)進(jìn)行拆分，設(shè)定調(diào)用時(shí)間周期

  
  
  時(shí)間片
  • 適用于運(yùn)行周期不同的任務(wù)，周期相對(duì)比較準(zhǔn)確
  • 任務(wù)不能阻塞
  • 每次調(diào)用都是同一個(gè)入口，也就是說一次調(diào)用是全部完成返回的
  • 執(zhí)行任務(wù)從時(shí)間上分散后可以增加“實(shí)時(shí)任務(wù)”的及時(shí)性

分散任務(wù)

#ifndef TASK_H
#define TASK_H

typedef void (*P_VOID_void)();

class Task{
  
private:
  int mPeri;
  volatile int mTick;
  P_VOID_void mProc;
  
public:
  Task( P_VOID_void proc, int peri=10 )
  { 
    mPeri = peri;
    mTick = peri; 
    mProc = proc;
  }

  void run()
  {
    if ( mTick <= 0 )
    {
      mTick = mPeri;
      mProc();
    }
  }

  void tick()
  {
    if ( mTick > 0 )
    { mTick--; }
  }
};

#define MAX_TASK_CNT 8

class Schedule
{
private:
  Task * mTasks[MAX_TASK_CNT];
  int mTaskCnt;
  
public:
  Schedule()
  {
    mTaskCnt = 0;
  }  
  
  void start()
  {
      TCCR1A = 0;          // normal operation
      TCCR1B = bit(WGM12) | bit(CS10) | bit(CS12);   // CTC, 1024
      OCR1A =  999;       // compare A register value (1000 * clock speed)
      TIMSK1 = bit (OCIE1A);             // interrupt on Compare A Match
  }

  void run()
  {
      int i;

      for ( i = 0; i < mTaskCnt; i++ )
      {
        mTasks[i]->run();
      }
  }

  void tick()
  {
      int i;

      for ( i = 0; i < mTaskCnt; i++ )
      {
        mTasks[i]->tick();
      }
  }

public:
  void attachTask( Task *pTask )
  {
    mTasks[ mTaskCnt ] = pTask;
    mTaskCnt++;
  } 
};

Schedule _schedule;

ISR(TIMER1_COMPA_vect)
{
  _schedule.tick();
}

#endif 

• 使用方法

#include <Task.h>
void task1()
{
  Serial.println("task1 "+String( millis() ));
}

void task2()
{
  Serial.println("task2 "+String( millis() ));
}

Task _task1( task1, 60 );
Task _task2( task2, 120 );

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);

  _schedule.attachTask( &_task1 );
  _schedule.attachTask( &_task2 );

  _schedule.start();
}

void loop() {
  // put your main code here, to run repeatedly:
  _schedule.run();
}

模塊的添加方法

• /libraries/模塊名稱
• /libraries/模塊名稱/src中放置源碼
• /libraries/模塊名稱/library.properties進(jìn)行模塊描述