STM32F437 and PI8 as output IO

[george239955_stm1]

Posted on June 08, 2018 at 16:37

Hi, guys.

I am using STM32F437 and trying to use PI8 as  an output port.

I am trying to program it using standard procedures:

 RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOI, ENABLE);

  GPIO_InitTypeDef  GPIO_InitStructure;  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;  GPIO_Init(GPIOI, &GPIO_InitStructure);  GPIOI->BSRRL=GPIO_Pin_8; // Set logical 1

As the result, I see always logical 0 on the output.

I know that this pin has some additional features from RTC.

What should I do to use this port as standard IO in output mode?

Regards, George.

 #stm32f437-and-pi8

[Tesla DeLorean]

Posted on June 08, 2018 at 18:10

It is in the low power domain is has low current drive capabilities.

What are you driving it into?

Use an external buffer.

In a no load condition, toggle it and scope

while(1) GPIOI->ODR ^=GPIO_Pin_8;

[george239955_stm1]

Posted on June 08, 2018 at 18:58

I have only an external 10k pullup resistor on this pin, its output is always logical 0.

What is wrong? Should I do anything additional to switch this pin to IO mode?

[Tesla DeLorean]

Posted on June 08, 2018 at 19:38

I don't believe there is anything special that needs to be done, it is not a part I have access to.

The PI8 pin is not bonded out in several packages, your part number is insufficiently complete for me to make a specific determination.

[T J]

Posted on June 09, 2018 at 01:30

on my new board PI8 is Tamper2, so it is a little special.

I didnt run it up yet, I hope it works...