SImple question #ifndef __STM32F100_Dicovery_H

[xtian]

Posted on January 18, 2013 at 02:11

what is this for

/**   ******************************************************************************   * @file    STM32vldiscovery.h   * @author  MCD Application Team   * @version V1.0.0   * @date    09/13/2010   * @brief   Header file for STM32vldiscovery.c module.   ******************************************************************************   * @copy   *   * THE PRESENT FIRMWARE WHICH IS FOR GUIDANCE ONLY AIMS AT PROVIDING CUSTOMERS   * WITH CODING INFORMATION REGARDING THEIR PRODUCTS IN ORDER FOR THEM TO SAVE   * TIME. AS A RESULT, STMICROELECTRONICS SHALL NOT BE HELD LIABLE FOR ANY   * DIRECT, INDIRECT OR CONSEQUENTIAL DAMAGES WITH RESPECT TO ANY CLAIMS ARISING   * FROM THE CONTENT OF SUCH FIRMWARE AND/OR THE USE MADE BY CUSTOMERS OF THE   * CODING INFORMATION CONTAINED HEREIN IN CONNECTION WITH THEIR PRODUCTS.   *   * <h2><center>&copy; COPYRIGHT 2010 STMicroelectronics</center></h2>   */   /* Define to prevent recursive inclusion -------------------------------------*/ &sharpifndef __STM32F100_Dicovery_H &sharpdefine __STM32F100_Dicovery_H //this one, is see this in every header... what is their function? &sharpifdef __cplusplus  extern ''C'' { &sharpendif /* Includes ------------------------------------------------------------------*/ &sharpinclude ''STM32f10x.h'' /** @addtogroup Utilities   * @{   */   /** @addtogroup STM32vldiscovery #new-question-=-new-thread #include-guard #include-guard #include-guard #learning-c

[xtian]

Posted on January 18, 2013 at 16:41

thanks guys for your help.. additional question

/* GPIOA Periph clock enable */   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);   /* Configure PA0 .. PA7 in output pushpull mode */   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;   GPIO_Init(GPIOA, &GPIO_InitStructure);   /* Configure PA8 .. PA15 in input, pulled up mode */   GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 | GPIO_Pin_11 | GPIO_Pin_12 | GPIO_Pin_13 | GPIO_Pin_14 | GPIO_Pin_15;   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;   GPIO_Init(GPIOA, &GPIO_InitStructure);   GPIOA->ODR = GPIOA->IDR >> 8; // Mirror high ordered inputs to low ordered outputs could you explain to me the bold one especially ''8'' and IDR

[Andrew Neil]

Posted on January 18, 2013 at 16:58

You should start a new thread for a new question - otherwise the thread title becomes meaningless, and it all gets very confusing...