Setting up the STM32's own hardware encoder interface

Here, channel 1 and channel 2 of TIM3 are used as level capture of AB items.

Since STM32 has its own hardware encoder interface, it can be used as long as it is set up. It is very powerful. The following program has passed the test.

void TIM3_Mode_Config(void)  

{  

    //u16 CCR1_Val = 2500;  

    //u16 CCR2_Val = 1000;  

    GPIO_InitTypeDef GPIO_InitStructure;  

  TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;  

    TIM_ICInitTypeDef TIM_ICInitStructure;  

    //TIM_OCInitTypeDef TIM_OCInitStructure;  

/*------------------------------------------------ ----------------*/  

    RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);  

  GPIO_StructInit(&GPIO_InitStructure);  

  /* Configure PA.06,07 as encoder input */  

  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;  

  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;  

  GPIO_Init(GPIOA, &GPIO_InitStructure);  

/*------------------------------------------------ ----------------*/      

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //Enable TIM3  

    TIM_DeInit(TIM3);  

    TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);  

  TIM_TimeBaseStructure.TIM_Period =0xffff; //  

  TIM_TimeBaseStructure.TIM_Prescaler =0; //Set prescaler:  

  TIM_TimeBaseStructure.TIM_ClockDivision =TIM_CKD_DIV1; //Set the clock division factor: no division  

  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //Upward counting mode  

  //TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_CenterAligned1;   

    /*Initialize TIM2 timer*/  

  TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);  

    /*------------------------------------------------ ------------------*/  

    //Encoding configuration encoding mode  

    TIM_EncoderInterfaceConfig(TIM3, TIM_EncoderMode_TI12,   

                             TIM_ICPolarity_Rising, TIM_ICPolarity_Rising); //TIM_ICPolarity_Rising rising edge capture  

  TIM_ICStructInit(&TIM_ICInitStructure);  

  TIM_ICInitStructure.TIM_ICFilter = 6; //Comparison filter  

  TIM_ICInit(TIM3, &TIM_ICInitStructure);  

    //TIM_ARRPreloadConfig(TIM3, ENABLE);  

 // Clear all pending interrupts  

  TIM_ClearFlag(TIM3, TIM_FLAG_Update);  

  TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE); //Enable interrupt  

  //Reset counter  

  TIM3->CNT =0;  

    TIM_Cmd(TIM3, ENABLE); //Enable timer 3  

}  

void TIM_Init(void)  

{  

  TIM3_Mode_Config();  

}
 

In the main program, send periodically through the serial port.  

int main(void)  
{  
  SystemInit(); // 72m clock  
  SysTick_Init();  
    TIM_Init();  
    NVIC_Config();  
    GPIO_74HC595_Config();  
  while (1)  
  {  
        encoder_num=TIM_GetCounter(TIM3);  
        
          
    // dis_595(encoder_num,encoder_num);  
          
  }  
}