【iCore4 雙核心板_ARM】例程五：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為推輓輸出模式，採

用灌電流方式與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 led_work_status;

  /* USER CODE END 1 */

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

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* 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();

  /* USER CODE BEGIN 2 */

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
  /* USER CODE END WHILE */

  /* USER CODE BEGIN 3 */
        if(systick.second_flag == 1){
            systick.second_flag = 0;
            led_work_status += 1;
            if(led_work_status > 2)led_work_status = 0;
            switch (led_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)
{
    //中斷時間1ms，每ims進入一次中斷
    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/1eSclNOI 密碼：cddu

iCore4連結：