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Newbie looking for help with GPIO

Question asked by Trace on Sep 1, 2014
Latest reply on Sep 22, 2014 by Trace

I have an STM32F4 Discovery board, which I am relatively new to.  I'm trying to figure out how to work with GPIO's, and I haven't been able to find a good tutorial yet, so I'm trying to work it out by looking at a few examples.

The problem I'm running into is that even duplicating just a few lines of code is causing me problems.  For reference, I'm using Keil MDK.


This is only an excerpt of some of the code, but I'm starting off with a working blinky project.  I've added the below lines:


#include "stm32f4xx_gpio.h"
 
GPIO_InitTypeDef  GPIO_InitStructure;
 
 
// in main():
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);




That last line that enables the peripheral clock is causing the following errors:


error:  use of undeclared identifier 'RCC_AHB1Periph_GPIOD'
warning:  implicit declaration of function 'RCC_AHB1PeriphClockCmd' is invalid in C99


I've tried searching, but I haven't found an explanation and solution to this.  What am I doing wrong?


----


As a second question, when I'm setting the project runtime environment, I see two different options for GPIO:

1.  Device\GPIO
2.  Device\StdPeriph Drivers\GPIO


What's the difference between the two and which one do I want?


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