Posted on January 31, 2018 at 22:43Just starting with STM32, my first 'blinky' program didn't work because of this same issue.
LL_GPIO_Init() is a bit of a mess. I changed it to make it work better. The key is looking at (only) bits 8..23
in GPIO_InitStruct->Pin to determine which of the I/O pins are requested.
By the way, I was puzzled that the function called LL_GPIO_SetPinSpeed() and LL_GPIO_SetPinOutputType() when mode
is LL_GPIO_MODE_FLOATING. Is there any way that could make sense, or is it indeed better to call these functions only
when the mode is LL_GPIO_MODE_OUTPUT ?
Below is the modified code for LL_GPIO_Init()
ErrorStatus LL_GPIO_Init(GPIO_TypeDef *GPIOx, LL_GPIO_InitTypeDef *GPIO_InitStruct)
{
uint32_t pinmask;
uint32_t pinpos;
uint32_t currentpin;
/* Check the parameters */
assert_param(IS_GPIO_ALL_INSTANCE(GPIOx));
assert_param(IS_LL_GPIO_PIN(GPIO_InitStruct->Pin));
assert_param(IS_LL_GPIO_MODE(GPIO_InitStruct->Mode));
assert_param(IS_LL_GPIO_PULL(GPIO_InitStruct->Pull));
/* make bitmask in which, for each requested I/O pin n, bit n is set */
pinmask = (GPIO_InitStruct->Pin & 0x00FFFF00U) >> 8 ;
/* Initialize pinpos on first bit that is set */
pinpos = POSITION_VAL(pinmask);
/* loop while any pins are left to configure */
while (( pinmask >> pinpos) != 0U)
{
/* skip if bit is not set */
if ((pinmask & (1U << pinpos)) == 0U)
{
pinpos++;
continue;
}
/* with pinpos the number of an I/O pin to configure, */
/* calculate the corresponding value of type GPIO_LL_EC_PIN (see stm32f1xx_ll_gpio.h) */
if (pinpos < 8 )
currentpin = (0x00000101U << pinpos);
else
currentpin = ((0x00010001U << (pinpos-8)) | 0x04000000U);
/* Pin Mode configuration */
LL_GPIO_SetPinMode(GPIOx, currentpin, GPIO_InitStruct->Mode);
/* Pull-up / Pull-down resistor configuration*/
LL_GPIO_SetPinPull(GPIOx, currentpin, GPIO_InitStruct->Pull);
if ((GPIO_InitStruct->Mode == LL_GPIO_MODE_OUTPUT) /*|| (GPIO_InitStruct->Mode == LL_GPIO_MODE_FLOATING)*/)
{
assert_param(IS_LL_GPIO_OUTPUT_TYPE(GPIO_InitStruct->OutputType));
/* Speed mode and output type configuration */
LL_GPIO_SetPinSpeed(GPIOx, currentpin, GPIO_InitStruct->Speed);
LL_GPIO_SetPinOutputType(GPIOx, currentpin, GPIO_InitStruct->OutputType);
}
pinpos++;
}
return (SUCCESS);
}
