GPIOS: Read pins as a port

Read four adjacent pins as a single port

The HAL library does not have a function to read an entire port, therefore we need to read one at a time and then accommodate each pin read in its respective bit using a variable

#include "bsp.h"

int main( void )
{
    GPIO_InitTypeDef GPIO_InitStruct;               /*gpios initial structure*/
    uint32_t Port;
    
    HAL_Init();                                     /*Init HAL library*/
    __HAL_RCC_GPIOB_CLK_ENABLE();                   /*Enable clock on port B*/
  
    GPIO_InitStruct.Pin   = 0x0F;                    /*pins B0 - B3 to set as input*/
    GPIO_InitStruct.Mode  = GPIO_MODE_INPUT;         /*input mode*/
    GPIO_InitStruct.Pull  = GPIO_NOPULL;             /*no pull-up niether pull-down*/
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;     /*pin speed*/
    /*use the previous parameters to set configuration on pin B0 and B3*/
    HAL_GPIO_Init( GPIOB, &GPIO_InitStruct );

    while(1)
    {
        /*Read the pin B0*/
        Port = HAL_GPIO_ReadPin( GPIOB, GPIO_PIN_0 );
        /*Read the pin B1 shift to the left by 1 and or with the previous value in Port variable*/
        Port |= ( HAL_GPIO_ReadPin( GPIOB, GPIO_PIN_1 ) << 1u );
        /*Read the pin B1 shift to the left by 2 and or with the previous value in Port variable*/
        Port |= ( HAL_GPIO_ReadPin( GPIOB, GPIO_PIN_2 ) << 2u );
        /*Read the pin B1 shift to the left by 3 and or with the previous value in Port variable*/
        Port |= ( HAL_GPIO_ReadPin( GPIOB, GPIO_PIN_3 ) << 3u );
        
        /*reads the four pins as a single port of fourt bits*/
        if( Port == SOME_VALUE )
        {
            /*the pin B0 to B3 as a port is equal to SOME_VALUE, do something*/
        }
        /*this is just a simple delay to avoid polling the pin to often*/
        HAL_Delay( 50 );
    }
}