Question
GPIO strange behaviour STM32F427
Posted on June 04, 2018 at 19:39
Hello,
i have a simple code where i just init some GPIO ports on a STM32F427VI ( 100pin package).
The application controls via pin PA8 some transistor which switches on/off a relay after some delay...
I have noticed if i configure PE2, then PA8 does not work ( does not switch to HI).
If i comment out the red code shown bellow, then PA8 works fine. Why is this? I have never encounter such problems with stm devices.
int main()
{SystemInit();
GPIO_InitTypeDef GPIO_InitStruct;RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA | RCC_AHB1Periph_GPIOC| RCC_AHB1Periph_GPIOD | RCC_AHB1Periph_GPIOB |RCC_AHB1Periph_GPIOE, ENABLE);// GPIOA & GPIOB clock enable
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_3 | GPIO_Pin_8; GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT; GPIO_InitStruct.GPIO_OType = GPIO_OType_PP; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_Init(GPIOA, &GPIO_InitStruct); GPIOA->BSRRL = GPIO_Pin_3 ; // PA3 Hi GPIOA->BSRRH = GPIO_Pin_8; // PA8 Lowfor(uint32_t o=0; o<0xFFFFFF; o++) { } // some delay
for(uint32_t o=0; o<0xFFFFFF; o++) { } // some delay GPIOA->BSRRL = GPIO_Pin_8; // PA8 hi GPIO_InitStruct.GPIO_Pin = GPIO_Pin_2; GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT; GPIO_InitStruct.GPIO_OType = GPIO_OType_OD; GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL; GPIO_Init(GPIOE, &GPIO_InitStruct);return 0;
}