GPIOS: Write an 8 bit Port

Example to write a value of 0xAA and then 0x55 on first 8 bits from port C.

As you notice we use the hexadecimal value 0x00FF and not the pin definitions, we can do that but the result will look like this:

GPIO_InitStruct.Pin = GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_2 | GPIO_PIN_3 | GPIO_PIN_4 | GPIO_PIN_5 | GPIO_PIN_6 | GPIO_PIN_7  ; 

Pretty long line indeed, just remember each pin define represent a bit from an entire 16 bits value, that is why we can use the or ( | ) operator to set several pins

#include "bsp.h"

int main(void)
{
    GPIO_InitTypeDef GPIO_InitStruct;               /*gpios initial structure*/
    
    HAL_Init();                                     /*Init HAL library*/
    __HAL_RCC_GPIOC_CLK_ENABLE();                   /*Enable clock on port C*/
  
    GPIO_InitStruct.Pin = 0x00FF;                   /*pins from 0 - 7 to set as output*/
    GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;     /*output on mode push-pull*/
    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 pins C0 - C7*/
    HAL_GPIO_Init( GPIOC, &GPIO_InitStruct );
    
    while (1)
    {
        /*Turn off pins from C0 to C7, second paramters of functions specify which leds will be RESET*/
        HAL_GPIO_WritePin( GPIOC, 0xFF, RESET );
        /*Write a value of 0xAA on port C pins from 0 to 7, second paramters of functions specify 
        which leds will be SET*/
        HAL_GPIO_WritePin( GPIOC, 0xAA, SET );
        /*Turn off pins from C0 to C7, again to write a new value*/
        HAL_GPIO_WritePin( GPIOC, 0xFF, RESET );
        /*Write value 0x55 on leds*/
        HAL_GPIO_WritePin( GPIOC, 0x55, SET );
    }
}