【iCore1S 雙核心板_ARM】例程十：SYSTICK定時器實驗——定時點亮LED

實驗原理：

　　通過STM32的三個GPIO口驅動三色LED的三個通道，設定GPIO為推輓輸出，採用

灌電流的方式與LED連線，輸出高電平LED滅，輸出低電平LED亮，通過系統定時器實現

1s定時，每秒變換一次LED顏色。

核心程式碼：

int main(void)
{

  /* USER CODE BEGIN 1 */
    static int work_status = 0;

  /* USER CODE END 1 */

  /* MCU Configuration----------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();                        //³õʼ»¯ËùÓÐÍâÉè

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();             //GPIO ³õʼ»¯

  /* USER CODE BEGIN 2 */

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    //ÿ¸ôÒ»ÃëÈýÉ«µÆ½øÐн»ÌæÑ­»·ÉÁ˸

  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */
        
        if(systick.second_flag == 1){
            systick.second_flag = 0;
            work_status += 1;
            if(work_status > 2)work_status = 0;
        }
        switch (work_status){
            case 0 :
                LED_RED_ON;
                LED_GREEN_OFF;
                LED_BLUE_OFF;
                break;
                
            case 1 :
                LED_RED_OFF;
                LED_GREEN_ON;
                LED_BLUE_OFF;
                break;
                
            case 2:
                LED_RED_OFF;
                LED_GREEN_OFF;
                LED_BLUE_ON;
                break;
                
            default:
                
                break;    
        }

  }
  /* USER CODE END 3 */

}

void HAL_SYSTICK_Callback(void)
{
    static int counter = 0;
    
    if((counter ++ % 1000) == 0){
        systick.second_flag = 1;
    }
}

原始碼下載連結：

連結：http://pan.baidu.com/s/1i51iVxb 密碼：70sj