[SOLVED] How to set GPIO input for infrared receiver

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GPIO PA15 input connnected to infrared receiver, I am using a NEC standard remote.

This code work with 2 different NEC remote command.

DelayUs function found on the post "Delay in us".

//***************************************************************************************
//* Infrared on PA15
//***************************************************************************************
uint32_t getUs(void) 
{
    uint32_t usTicks = HAL_RCC_GetSysClockFreq() / 1000000;
 
    register uint32_t ms, cycle_cnt;
 
    do {
       ms = HAL_GetTick();
 
       cycle_cnt = SysTick->VAL;
 
   } while (ms != HAL_GetTick());
 
   return (ms * 1000) + (usTicks * 1000 - cycle_cnt) / usTicks;
}
 
void delayUs(uint16_t micros) 
{
   uint32_t start = getUs();
 
   while (getUs()-start < (uint32_t) micros) 
   {
      __asm("nop");
   }
}
 
void EXTI15_10_IRQHandler(void)
{
#define MAX_NEG_START  (10000)
#define MIN_NEG_START  (8000)
#define MAX_POS_START  (5000)
#define MIN_POS_START  (3500)
#define MAX_POS_REP    (2500)
#define MIN_POS_REP    (1500)
#define MIN_POS_BIT1   (1200) 
#define DELAY_STEP     (250)
 
  int   IR;
  int   l, k, counter;
  unsigned char  data1, data2, addr1, addr2;
 
  //HAL_SuspendTick();
 
  HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_15);
 
  for (k = 0; k < MAX_NEG_START && !HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_15); k += DELAY_STEP)
  {
          delayUs(DELAY_STEP);
  }
 
  if ((k < MAX_NEG_START) && (k > MIN_NEG_START))
  {
      for (l = 0; l < MAX_POS_START && HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_15); l += DELAY_STEP)
      {
          delayUs(DELAY_STEP);
      } 
 
      if (l < MAX_POS_REP && l > MIN_POS_REP)
      {
    	  while(!HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_15));
 
   	  if (save_addr1 > 0)
	  {
	     IR_addr1 = save_addr1;
	     IR_addr2 = save_addr2;
	  }
          time1 = k;  // only for debug time
          time2 = l;
	  return;
      }
 
      if ((l < MAX_POS_START) && (l > MIN_POS_START))
      {
          while (!HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_15));
 
          addr1 = IR_readByte(0, MIN_POS_BIT1);
 
          addr2 = IR_readByte(1, MIN_POS_BIT1);
 
          data1 = IR_readByte(0, MIN_POS_BIT1);
 
          data2 = IR_readByte(1, MIN_POS_BIT1);
 
#if OLD_REMOTE
         if (addr1 != addr2) return;
#endif
         if (data1 != data2) return;
 
         if (addr1 == 0)  return;
         if (data1 == 0)  return;
 
         save_addr1 = addr1;
         save_addr2 = addr2;
 
         IR_addr1 = addr1;
         IR_addr2 = addr2;
         IR_data1 = data1;
         IR_data2 = data2;
 
         time1 = k;  // only for debug time
         time2 = l;
      }
  }
}
 
unsigned char IR_readByte(int inv, int CheckTime)
{
    unsigned char out, tmp[10];
    int i, k, counter;
 
    for (k = 0; k < 8; k++)
    {
	for (i = 0; HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_15); i += DELAY_STEP)
	{
	    delayUs(DELAY_STEP);
	}
        while (!HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_15));
 
        if (i > CheckTime)
        {
	    if (inv == 0 ) 
		tmp[k] = '1';
	    else
                tmp[k] = '0';
        }
        else
        {
	    if (inv == 0 ) 
		tmp[k] = '0';
	    else
                tmp[k] = '1';
 
        }
    }
    out = 0;
 
    for (k = 7; k >= 0; k--)
    {
	if (tmp[k] == '1')
	{
	    out <<= 1; out |= 1;
	}
	else
	{
	    out <<= 1;
	}
    }
    return out;
}
 
 
void BSP_IR_Init()
{
  GPIO_InitTypeDef  gpio_init_structure;
 
  __HAL_RCC_GPIOA_CLK_ENABLE();
 
  gpio_init_structure.Pin = GPIO_PIN_15;
  gpio_init_structure.Mode = GPIO_MODE_IT_FALLING;
  gpio_init_structure.Pull = GPIO_NOPULL;
 
  HAL_GPIO_Init(GPIOA, &gpio_init_structure);
 
  HAL_NVIC_SetPriority(EXTI15_10_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(EXTI15_10_IRQn);
}
//***************************************************************************************
//* end - Infrared
//***************************************************************************************