[SOLVED] How to set GPIO input for infrared receiver

[Ciuffoly]

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
//***************************************************************************************