/**
  ******************************************************************************
  * @file    main.c
  * @author  Ac6
  * @version V1.0
  * @date    01-December-2013
  * @brief   Default main function.
  ******************************************************************************
*/


#include "stm32f4xx.h"
void Delay(__IO uint32_t cnt);

// init the GPIO struct, this needs to be done for all peripherals
GPIO_InitTypeDef GPIO_InitStructure;

int main(void){

// setip the AHB bus and the GPIO for blinking
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOD, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_12| GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOD, &GPIO_InitStructure);

while (1){

GPIO_SetBits(GPIOD,GPIO_Pin_12);
GPIO_ResetBits(GPIOD, GPIO_Pin_13);
Delay(0x3fffff);
GPIO_SetBits(GPIOD,GPIO_Pin_13);
GPIO_ResetBits(GPIOD, GPIO_Pin_12);
Delay(0x3fffff);
GPIO_SetBits(GPIOD,GPIO_Pin_14);
GPIO_ResetBits(GPIOD, GPIO_Pin_15);
Delay(0x3fffff);
GPIO_SetBits(GPIOD,GPIO_Pin_15);
GPIO_ResetBits(GPIOD, GPIO_Pin_14);
Delay(0x3fffff);
}
}

// hanging delay
void Delay(__IO uint32_t cnt)
{
while(cnt--)
{
}
}