Stm32cube infrared remote control: input capture

STM32Cube infrared remote control ： Input capture

The principle of infrared remote control ：https://blog.csdn.net/yangyang_1024/article/details/82999694
chip :stm32f030F4PX
Capture channels ：TIM3_CH1

• Use the internal clock , when ,stm32f030F4PX The maximum clock frequency is 48MHz, The clock frequency of this configuration is 48MHz, The clock configuration is as follows ：
  
• Configure the input capture channel , There is no need to check the external clock to select the internal clock Internal Clock, Select the channel 1Channel1, The model is Inp Captur direct mode.
  
• Timer parameter configuration ,48 frequency division , Count up , prescale 65535 namely 0xFFFF, This is a 16 Bit count, so the maximum value is 65535. No counting unit is 1us, Enable update interrupt .
  
  
  
• The generated code
  
  - Source code reference punctual atom , The code is as follows
  -1. Turn on input capture

__HAL_TIM_SET_CAPTUREPOLARITY(&htim3,TIM_CHANNEL_1,TIM_INPUTCHANNELPOLARITY_RISING);
  HAL_TIM_IC_Start_IT(&htim3, TIM_CHANNEL_1);

2. Input capture processing

void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
  if (htim->Instance == TIM3)
  {
    if (RmtSta & 0x80) // Last time data was received 
    {
      RmtSta &= ~0X10; // Cancel rising edge has been marked by capture 
      if ((RmtSta & 0X0F) == 0X00)
        RmtSta |= 1 << 6; // Mark that the key value information collection of a key has been completed 
      if ((RmtSta & 0X0F) < 14)
        RmtSta++;
      else
      {
        RmtSta &= ~(1 << 7); // Clear the guide sign 
        RmtSta &= 0XF0;      // Clear the counter 
      }
    }
  }
}

void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim)
{
  if (TIM3 == htim->Instance)
  {
    if (HAL_TIM_ACTIVE_CHANNEL_1 == htim->Channel)
    {

      if (HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_6))// Judge the level of the capture pin 
      {

        __HAL_TIM_SET_CAPTUREPOLARITY(&htim3, TIM_CHANNEL_1, TIM_INPUTCHANNELPOLARITY_FALLING);// Falling edge capture 
        __HAL_TIM_SET_COUNTER(&htim3, TIM_CHANNEL_1); // Set the value of the count register to 0

        RmtSta |= 0x10;
      }
      else
      {
        Dval = HAL_TIM_ReadCapturedValue(&htim3, TIM_CHANNEL_1);// Get the time from falling edge to rising edge  
        g_recvIRTime = __HAL_TIM_GET_COMPARE(&htim3, TIM_CHANNEL_1);
        __HAL_TIM_SET_CAPTUREPOLARITY(&htim3, TIM_CHANNEL_1, TIM_INPUTCHANNELPOLARITY_RISING);// Rising edge capture 

        if (RmtSta & 0x10)
        {
          if (RmtSta & 0x80)
          {
            uint8_t Index = g_recvIndex / 8;
            if ((Dval > 300) && (Dval < 800))//  position 1
            {

              if (g_recvIndex != 0)
                g_recvBuf[Index] <<= 1;
              g_recvBuf[Index] &= 0xfe;
              g_recvIndex++;
              // g_recvIndex_0 ++;
            }
            else if ((Dval > 1400) && (Dval < 1800))//  position 0
            {

              g_recvIndex++;
              g_recvBuf[Index] <<= 1;
              g_recvBuf[Index] |= 1;
            }
            else if ((Dval > 2000) && (Dval < 2500))
            {

              RmtCnt++; //  Repeat code 
              RmtSta &= 0xf0;
            }
          }
          else if ((Dval > 4200) && (Dval < 4700))
          {
            RmtSta |= 1 << 7; // Indicates that the synchronization header has been received 
            RmtCnt = 0;       // Reset the number of keys 
            RmtRec = 0;
            g_recvIndex = 0;
          }
        }
        RmtSta &= ~(1 << 4);
      }
    }
  }
}
void Remote_Scan(void)
{
  uint8_t flag, state = 0;
  flag = ~g_recvBuf[1];
  static int staLCDstate = 0;
  staLCDstate = ~staLCDstate;
  if (g_recvIndex == 32)// Completion of reception 
  {
    if (g_recvBuf[0] == flag)// User judgment 
    {
      flag = ~g_recvBuf[3];
      if (g_recvBuf[2] == flag)// Key code judgment 
      {
        switch (g_recvBuf[2])
        {

        case KEY_POWER:
          if (RmtCnt < 12)// Long press 
          {
            LCD_ON;
          }
          else
          {
            LCD_OFF;
          }
          break;
          default:
          break;
        }
      }
    }
  }
}

STM32Cube Engineering and code connections ：https://download.csdn.net/download/jjjjjj0000/15659644?spm=1001.2014.3001.5501