基于STM32F411+WM8978的超小MP3播放器

int main(void) {
   uint8_t error_cnt = 0,res;
   PowerOnSequence();
   WDT_Init();//在SD卡读取与暂停时喂狗
   res = WM8978_Init();
   if(res) { //WM8978初始化失败
      LED_SetBlinkPattern(LED_BLINK_WARNING);
      Delay_WithFeedingDog();
      return 1;
   }
   while(1) {
      res = f_mount(&fatfs,"",1);//尝试挂载文件系统
      if(res) { //失败
         if(error_cnt == 1) {
            LED_SetBlinkPattern(LED_BLINK_ERROR);
         }
         error_cnt ++;
         delay_ms(100);
         if(error_cnt > 100) {
            return 1;
         }
         if(AudioPlayInfo.PlayRes == AudioPlay_Exit) {
            return 1;
         }
         continue;
      }
      LED_SetBlinkPattern(LED_BLINK_CLEAR);
      error_cnt = 0;
      MP3_Player();
      if(AudioPlayInfo.PlayRes == AudioPlay_Exit) { //播放器退出
         return 1;
      }
   }
}

void PowerOnSequence(void)
{
   uint8_t boot_cnt = 0;
   uint8_t batt_percrntage;
   
   /*初始化硬件*/
   delay_init();
   Power_Init();
   KEY_GPIO_Init();
   LED_PWM_Init();
   batt_percrntage = Power_GetBattPercentage();
   srand(Power_GetRandSeed());//随机数种子
   while(1) { //充电与开机循环
      if(!PWR_PGOOD) { //插入适配器 开始关机充电
         Power_AdapterStatus = 1;
         while(1) { //充电过程
         
            Power_Switch(1);
            if(PWR_CHRG == 0) { //正在充电
               LEDR(255); LEDB(0);
            }
            else { //充满
               LEDR(0); LEDB(255);
            }
            if(KEY_PLAY_PIN) { //按下开机键
               LEDB(0); LEDR(0);
               break;//退出充电
            }
            if(PWR_PGOOD) { //拔出充电器
               Power_Switch(0);//关闭电源
            }
         }
      }
      while(KEY_PLAY_PIN) { //开机过程
         if(boot_cnt <= 100) { //长按计数
            boot_cnt ++;
         }
         delay_ms(10);
         if(boot_cnt > 100) { //成功开机
            Power_Switch(1);//开启电源
            if(batt_percrntage >= 30){//根据电量亮灯
               LEDB(255); LEDR(255);
            }
            else if(batt_percrntage > 0) { //电池电量低
               LEDR(255);
            }
            else {
               continue;//拒绝开机
            }
         }
      }
      if(boot_cnt > 100) { //成功开机
         break;
      }
      boot_cnt = 0;
   }
   delay_ms(1000);
   LEDB(0);LEDR(0);
   KEY_Timer_Init();
}

AudioPlayRes MP3_Player(void)
{	
   static uint8_t file_error_cnt;
   NumberOfFolders = ReadRootDir();
   CurrentMusic = 0;
   CurrentFolder = 0;
   while(1) { //文件夹切换
      FolderSwitchProc();//切换文件夹
      NumberOfMusics = ReadFileList(FolderList[CurrentFolder]);//切换文件夹
      if(NumberOfMusics == 0) { //当前是空文件夹
         continue;//继续执行上一次的文件夹操作
      }
      file_error_cnt = 0;//复位错误计数
      RandomPlay_Reset();//复位随机播放
      LastValidPlayRes = AudioPlay_Next;//默认下一曲
      while(1) { //曲目切换
         MusicSwitchProc();//切换乐曲
         AudioPlayFile(FolderList[CurrentFolder],FileList[CurrentMusic]);//播放
         if(AudioPlayInfo.PlayRes == AudioPlay_NextFolder || AudioPlayInfo.PlayRes == AudioPlay_PrevFolder) { //若切换文件夹 则退出循环
            break;
         }
         else if(AudioPlayInfo.PlayRes == AudioPlay_Exit || AudioPlayInfo.PlayRes == AudioPlay_OpenFileError || AudioPlayInfo.PlayRes == AudioPlay_ReadFileError) { //播放结束
            return AudioPlayInfo.PlayRes;
         }
         else if(AudioPlayInfo.PlayRes == AudioPlay_Next || AudioPlayInfo.PlayRes == AudioPlay_Prev) {
            LastValidPlayRes = AudioPlayInfo.PlayRes;//保存上一次的正常操作
         }
         else if(AudioPlayInfo.PlayRes != AudioPlay_OK && AudioPlayInfo.PlayRes != AudioPlay_PlayEnd) { //播放出错
            AudioPlayInfo.PlayRes = LastValidPlayRes;//按照上一次操作重新操作 达到跳过的效果
            file_error_cnt ++;
            if(file_error_cnt > 5)//连续错误5次达到阈值
            {
               //错误处理代码
            }
         }
      }
   }
}

void TIM2_IRQHandler(void)
{
   static Key_Status status = {Key_None,Key_None,0,0};
   LED_BlinkPattern led_pattern = {blink_none		,	0,	0};
   if(TIM_GetITStatus(TIM2, TIM_IT_Update) != RESET) { //检查TIM2更新中断发生与否
      led_pattern = Power_Check();//检测电源插入
      status.pressed_key = Key_Scan();//记录按键值
      if(status.pressed_key == Key_None && !status.last_key) { //按键完全抬起之后
         status.long_pressed = 0;
      }
      if(status.pressed_key) { //如果按键按下了
         if(!status.long_pressed) { //当前还未触发长按事件
            status.long_press_cnt ++;
            if(status.long_press_cnt >= KEY_SCAN_LONGPRESS_TRIGGER_TICKS) {
               led_pattern = Key_LongPress_Callback(status.pressed_key);//长按按键事件
               status.long_pressed = 1;
            }
         }
      } else {
         status.long_press_cnt = 0;
      }
      if(status.last_key && (status.pressed_key == Key_None) && !status.long_pressed) { //按键抬起边沿 并且没有触发过长按事件
         led_pattern = Key_ShortPress_Callback(status.last_key);//按键短按事件
      }
      status.last_key = status.pressed_key;//按下时不记录按键状态
      LED_Process(led_pattern);//处理LED闪烁
      TIM_ClearITPendingBit(TIM2, TIM_IT_Update);//清除TIMx更新中断标志
   }
}