Question

我想创建自己的驱动程序，其中包含一个.c文件和一个.h文件。 .c文件是：

#include <msp430f5438a.h>
#include "ports_init.h"

extern void set_all_ports(unsigned char direction, unsigned char state)
{
   P1DIR = direction;
   P2DIR = direction;
   P3DIR = direction;
   P4DIR = direction;
   P5DIR = direction;
   P6DIR = direction;
   P7DIR = direction;
   P8DIR = direction;
   P9DIR = direction;
   P10DIR = direction;
   P11DIR = direction;
   PJDIR = direction; 

   P1OUT = state;
   P2OUT = state;
   P3OUT = state;
   P4OUT = state;
   P5OUT = state;
   P6OUT = state;
   P7OUT = state;
   P8OUT = state;
   P9OUT = state;
   P10OUT = state;
   P11OUT = state;
   PJOUT = state;
}

.h文件是：

#ifndef _PORTS_INIT_
#define _PORTS_INIT_

//Function prototypes
void set_all_ports(unsigned char direction, unsigned char state);

#define HIGH_STATE   0xFFu
#define LOW_STATE    0x00u

#define OUTPUTS      0xFFu
#define INPUTS       0x00u

#endif

我的代码是：

#include <msp430f5438a.h>
#include "ports_init.h"
int main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog timer
  P4DIR |= 0x03;                            // Set P2.0 to output direction
  P4OUT = 0x00;

  P1DIR &= ~BIT7;
  P1REN = BIT7;
  P1OUT = BIT7;  
  set_all_ports(OUTPUTS, LOW_STATE);
  while (1)                                 
     ;
}

不幸的是，当我编译我的源代码时，我收到错误：错误[e46]：未定义的外部＆＃34; set_all_ports＆＃34;在GPIO主要提到。我的问题是如何修改我的.c和.h文件，以使此错误消失。我知道将.c文件包含在我的源代码中并不是一个好习惯。这就是为什么我想通过在源代码中仅包含ports_init.h来调用驻留在ports_init.c中的函数，就像在真实的API中一样。我正在为MSP430使用IAR嵌入式工作台。请原谅我糟糕的英语，我希望你明白这一点。

Answer 1

我要说的问题是你的.c文件中你将该函数声明为extern void，我认为它应该是无效的

错误[e46]：未定义的外部＆＃34; set_all_ports＆＃34;在GPIO主要提到

1 个答案: