_105_timer.md

Topic

• Timer overview for stm32f103c8t6
• CubeMX setup a general timer
• Coding with timer 2
• Code:
  • ../Code/_105_timer
• Test
  • timer pooling, toggle led each 1s: ../Test/_105_timer_pooling.mp4

Timer overview

• 
• With stm32f103C8t6 we have 4 timer:
  • Advanced Control: TIM1 using APB2
  • General purpose: TIM 2 - TIM 4 using APB1
• 
• Clock frequency for stm32f103C8t6:
  • 

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Set up a general timer

• clock config 72MHz for APB1:
• 
• Then configure the TIM2 countup each 1us:
• 
• Then check generate .c and .h file:
• 
• (If interrupt mode) tick to enable interrupt
• 

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Coding with timer 2

• Now in project we have tim.h and tim.c
• In folder driver for stm32f103 find the stm32f1xx_hal_tim.h list all APIs for timer.

1. Something worth noting

The tim.h

• extern TIM_HandleTypeDef htim2;
• void MX_TIM2_Init(void);

The stm32f1xx_hal_tim.h

    /* Blocking mode: Polling */
    HAL_StatusTypeDef HAL_TIM_Base_Start(TIM_HandleTypeDef *htim);
    HAL_StatusTypeDef HAL_TIM_Base_Stop(TIM_HandleTypeDef *htim);
    /* Non-Blocking mode: Interrupt */
    HAL_StatusTypeDef HAL_TIM_Base_Start_IT(TIM_HandleTypeDef *htim);
    HAL_StatusTypeDef HAL_TIM_Base_Stop_IT(TIM_HandleTypeDef *htim);
    /* Non-Blocking mode: DMA */
    HAL_StatusTypeDef HAL_TIM_Base_Start_DMA(TIM_HandleTypeDef *htim, uint32_t *pData, uint16_t Length);
    HAL_StatusTypeDef HAL_TIM_Base_Stop_DMA(TIM_HandleTypeDef *htim);

    // Callback in non blocking modes (Interrupt and DMA)
    void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim);
    void HAL_TIM_PeriodElapsedHalfCpltCallback(TIM_HandleTypeDef *htim);