串口通信出现.. Undefined symbol USART_RX_BUF 错误，请大神带路

渣渣 · 发表于 2016-9-26 17:06:27

#include "sys.h"
#include "usart.h"
#include "dht11.h"

#if SYSTEM_SUPPORT_UCOS
#include "includes.h"
#endif

#if 1
#pragma import(__use_no_semihosting)

struct __FILE
{
int handle;

};

FILE __stdout;
_sys_exit(int x)
{
x = x;
}

int fputc(int ch, FILE *f)
{
while((USART1->SR&0X40)==0);//Ñ-»··￠Ëí,Ö±μ½·￠Ëííê±Ï
USART1->DR = (u8) ch;
return ch;
}
#endif
/*
int fputc(int ch, FILE *f)
{
USART_SendData(USART1, (uint8_t) ch);

while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET) {}

return ch;
}
int GetKey (void)  {

while (!(USART1->SR & USART_FLAG_RXNE));

return ((int)(USART1->DR & 0x1FF));
}
*/

extern u8  USART_RX_BUF[USART_REC_LEN];    //½óêÕ»o3å,×î′óUSART_REC_LEN¸ö×Ö½ú.

u16 USART_RX_STA=0;
void uart_init(u32 bound){
GPIO_InitTypeDef GPIO_InitStructure;
   USART_InitTypeDef USART_InitStructure;
   NVIC_InitTypeDef NVIC_InitStructure;

   RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1|RCC_APB2Periph_GPIOA|RCC_APB2Periph_AFIO , ENABLE); //ê1ÄüUSART1￡¬GPIOAê±Öó
   USART_DeInit(USART1);  //¸′Î»′®¿ú1
   //USART1_TX PA.9
    GPIO_PinRemapConfig(GPIO_Remap_USART1,ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9; //PA.9
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //¸′óÃíÆíìêä3ö
GPIO_Init(GPIOA, &GPIO_InitStructure); //3õê¼»ˉPA9

//USART1_RX    PA.10
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;//¸¡¿Õêäèë
GPIO_Init(GPIOA, &GPIO_InitStructure);  //3õê¼»ˉPA10

//Usart1 NVIC ÅäÖÃ

NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;
   NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=3 ;//ÇàÕ¼óÅÏè¼¶3
   NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3; //×óóÅÏè¼¶3
   NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //IRQí¨μàê1Äü
   NVIC_Init(&NVIC_InitStructure); //¸ù¾YÖ¸¶¨μÄ2Îêy3õê¼»ˉVIC¼Ä′æÆ÷

//USART 3õê¼»ˉéèÖÃ

   USART_InitStructure.USART_BaudRate = bound;//ò»°ãéèÖÃÎa9600;
   USART_InitStructure.USART_WordLength = USART_WordLength_8b;//×Ö3¤Îa8Î»êy¾Y¸ñê½
   USART_InitStructure.USART_StopBits = USART_StopBits_1;//ò»¸öí￡Ö1Î»
   USART_InitStructure.USART_Parity = USART_Parity_No;//ÎTÆæÅ¼D￡ÑéÎ»
   USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;//ÎTó2¼têy¾Yá÷¿ØÖÆ
   USART_InitStructure.USART_Mode = USART_Mode_Rx ; //êÕ·￠Ä￡ê½

USART_Init(USART1, &USART_InitStructure); //3õê¼»ˉ′®¿ú
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//¿aÆôÖD¶Ï
USART_Cmd(USART1, ENABLE);                   //ê1Äü′®¿ú

}
#if EN_USART1_RX //èç1ûê1ÄüáË½óêÕ
void USART1_IRQHandler(void)             //′®¿ú1ÖD¶Ï·tÎñ3ìDò
{
u8 Res;

#ifdef OS_TICKS_PER_SEC      //èç1ûê±Öó½úÅÄêy¶¨òåáË,ËμÃ÷òaê1óÃucosIIáË.
OSIntEnter();
#endif
if(USART_GetITStatus(USART1, USART_IT_RXNE) != RESET)  //½óêÕÖD¶Ï(½óêÕμ½μÄêy¾Y±ØDëêÇ0x0d 0x0a½áÎ2)
{
Res =USART_ReceiveData(USART1);//(USART1->DR); //¶áè¡½óêÕμ½μÄêy¾Y

if((USART_RX_STA&0x8000)==0)//½óêÕÎ′íê3é
{
if(USART_RX_STA&0x4000)//½óêÕμ½áË0x0d
{
if(Res!=0x0a)USART_RX_STA=0;//½óêÕ′íÎó,ÖØDÂ¿aê¼
else USART_RX_STA|=0x8000; //½óêÕíê3éáË
}
else //»1Ã»êÕμ½0X0D
{
if(Res==0x0d)USART_RX_STA|=0x4000;
else
{
USART_RX_BUF[USART_RX_STA&0X3FFF]=Res ;
USART_RX_STA++;

if(USART_RX_STA>(USART_REC_LEN-1))USART_RX_STA=0;//½óêÕêy¾Y′íÎó,ÖØDÂ¿aê¼½óêÕ
}
}
}
   }
#ifdef OS_TICKS_PER_SEC      //èç1ûê±Öó½úÅÄêy¶¨òåáË,ËμÃ÷òaê1óÃucosIIáË.
OSIntExit();
#endif
}
#endif

u8 DHT11_Read_Data(u8 *temp,u8 *humi)
{
u8 buf[5];
u8 res;
u8 i,t;
DHT11_Rst();
if(DHT11_Check()==0)
{
for(i=0;i<5;i++)//¶áè¡40Î»êy¾Y
{

res= USART_RX_BUF ;
buf=res;

}
if((buf[0]+buf[1]+buf[2]+buf[3])==buf[4])
{
*humi=buf[0];
*temp=buf[2];
}
}else return 1;
return 0;
}
程序在编译时出现..\OBJ\USART.axf: Error: L6218E: Undefined symbol USART_RX_BUF (referred from usart.o).就是说res= USART_RX_BUF ;中USART_RX_BUF 没有定义，可是extern u8  USART_RX_BUF[USART_REC_LEN];明明定义的全局变量，为什么出现这样的错误，请大神带路，谢谢