第二篇就是熟悉一下定时器，这都是常用的功能外设，当然验证定时器的中断还是得用LED灯才能看到效果。看Datasheet的话，会发现芯片有16个定时器。先试试16bit普通的定时器中断。

首先初始化库，时钟配置，如下所示：

1. /** System Clock Configuration
   
2. */
   
3. void SystemClock_Config(void)
   
4. {
   
5. 
   
6.   RCC_OscInitTypeDef RCC_OscInitStruct;
   
7.   RCC_ClkInitTypeDef RCC_ClkInitStruct;
   
8. 
   
9.     /**Initializes the CPU, AHB and APB busses clocks
   
10.     */
    
11.   RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
    
12.   RCC_OscInitStruct.HSEState = RCC_HSE_BYPASS;
    
13.   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
    
14.   RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
    
15.   RCC_OscInitStruct.PLL.PLLM = 1;
    
16.   RCC_OscInitStruct.PLL.PLLN = 20;
    
17.   RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
    
18.   RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
    
19.   RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
    
20.   if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    
21.   {
    
22.     Error_Handler();
    
23.   }
    
24. 
    
25.     /**Initializes the CPU, AHB and APB busses clocks
    
26.     */
    
27.   RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
    
28.                               |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
    
29.   RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
    
30.   RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    
31.   RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV16;
    
32.   RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
    
33. 
    
34.   if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
    
35.   {
    
36.     Error_Handler();
    
37.   }
    
38. 
    
39.     /**Configure the main internal regulator output voltage
    
40.     */
    
41.   if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
    
42.   {
    
43.     Error_Handler();
    
44.   }
    
45. 
    
46.     /**Configure the Systick interrupt time
    
47.     */
    
48.   HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/1000);
    
49. 
    
50.     /**Configure the Systick
    
51.     */
    
52.   HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);
    
53. 
    
54.   /* SysTick_IRQn interrupt configuration */
    
55.   HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
    
56. }

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初始化引脚：

1. GPIO_InitTypeDef GPIO_InitStruct;
   
2. 
   
3.   /* GPIO Ports Clock Enable */
   
4.   __HAL_RCC_GPIOH_CLK_ENABLE();
   
5.   __HAL_RCC_GPIOB_CLK_ENABLE();
   
6. 
   
7.   /*Configure GPIO pin Output Level */
   
8.   HAL_GPIO_WritePin(GPIOB, GPIO_PIN_14, GPIO_PIN_RESET);
   
9. 
   
10.   /*Configure GPIO pin : PB14 */
    
11.   GPIO_InitStruct.Pin = GPIO_PIN_14;
    
12.   GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
    
13.   GPIO_InitStruct.Pull = GPIO_NOPULL;
    
14.   GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    
15.   HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

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初始化定时器2：

1. TIM_ClockConfigTypeDef sClockSourceConfig;
   
2.   TIM_MasterConfigTypeDef sMasterConfig;
   
3. 
   
4.   htim2.Instance = TIM2;
   
5.   htim2.Init.Prescaler = 9999;
   
6.   htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
   
7.   htim2.Init.Period = 999;
   
8.   htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
   
9.   if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
   
10.   {
    
11.     Error_Handler();
    
12.   }
    
13. 
    
14.   sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
    
15.   if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
    
16.   {
    
17.     Error_Handler();
    
18.   }
    
19. 
    
20.   sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
    
21.   sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
    
22.   if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
    
23.   {
    
24.     Error_Handler();
    
25.   }
    
26.   HAL_TIM_Base_Start_IT(&htim2);

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中断响应部分：

1. void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
   
2. {
   
3.      HAL_GPIO_TogglePin(GPIOB,GPIO_PIN_14);
   
4.     /* Insert delay 100 ms */
   
5. //    HAL_Delay(100);
   
6. }

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效果如图