串口的printf函数不能用

关山难越 · 发表于 2018-8-29 15:04:26

用了原子哥的407的串口示例代码，引脚连接也没有什么错误，但是printf函数就是不能使用，USART_SendData(USART1,0x34)发送一个字节过后就一直是错误的显示在串口助手上，我什么也没有改啊
非常疑惑，哪里有问题，接收函数都是没有问题的，我通过上位机发送 Q  S 能控制灯，就是printf 和  USART_SendData（）用不了          请求指教

int main(void)
{
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);
delay_init(168);
uart_init(115200);
LED_Init();
while(1)
{
/       /printf("nYYY\n");
USART_SendData(USART1,0x34);
//delay_ms(100);
}
}

[mw_shl_code=applescript,true]void uart_init(u32 bound){
//GPIO¶Ë¿úéèÖÃ
  GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;

RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA,ENABLE); //ê1ÄüGPIOAê±Öó
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1,ENABLE);//ê1ÄüUSART1ê±Öó

//′®¿ú1¶Ôó|òy½Å¸′óÃó3éä
GPIO_PinAFConfig(GPIOA,GPIO_PinSource9,GPIO_AF_USART1); //GPIOA9¸′óÃÎaUSART1
GPIO_PinAFConfig(GPIOA,GPIO_PinSource10,GPIO_AF_USART1); //GPIOA10¸′óÃÎaUSART1

//USART1¶Ë¿úÅäÖÃ
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10; //GPIOA9óëGPIOA10
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;//¸′óÃ1|Äü
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //Ëù¶è50MHz
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP; //íÆíì¸′óÃêä3ö
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN; //éÏà-
GPIO_Init(GPIOA,&GPIO_InitStructure); //3õê¼»ˉPA9￡&#172

A10

//USART1 3õê¼»ˉéèÖÃ
USART_InitStructure.USART_BaudRate = bound;//2¨ìØÂêéèÖÃ
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 | USART_Mode_Tx; //êÕ·￠Ä￡ê½
  USART_Init(USART1, &USART_InitStructure); //3õê¼»ˉ′®¿ú1

  USART_Cmd(USART1, ENABLE);  //ê1Äü′®¿ú1

//USART_ClearFlag(USART1, USART_FLAG_TC);
#if EN_USART1_RX
USART_ITConfig(USART1, USART_IT_RXNE, ENABLE);//¿aÆôÏà1ØÖD¶Ï

//Usart1 NVIC ÅäÖÃ
  NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQn;//′®¿ú1ÖD¶Ïí¨μà
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÷¡￠

#endif

}[/mw_shl_code]

[mw_shl_code=applescript,true]void USART1_IRQHandler(void)             //′®¿ú1ÖD¶Ï·tÎñ3ìDò
{
if(USART_ReceiveData(USART1)=='S')
{
GPIO_SetBits(GPIOD,GPIO_Pin_12 | GPIO_Pin_13| GPIO_Pin_14| GPIO_Pin_15);
}
if(USART_ReceiveData(USART1)=='Q')
{
GPIO_ResetBits(GPIOD,GPIO_Pin_12 | GPIO_Pin_13| GPIO_Pin_14| GPIO_Pin_15);
} [/mw_shl_code]

[mw_shl_code=applescript,true]#if 1
#pragma import(__use_no_semihosting)
//±ê×¼¿aDèòaμÄÖ§3Öoˉêy
struct __FILE
{
int handle;
};

FILE __stdout;
//¶¨òå_sys_exit()òÔ±üÃaê1óÃ°ëÖ÷»úÄ￡ê½
void _sys_exit(int x)
{
x = x;
}
//ÖØ¶¨òåfputcoˉêy
int fputc(int ch, FILE *f)
{
while((USART1->SR&0X40)==0);//Ñ-»··￠Ëí,Ö±μ½·￠Ëííê±Ï
USART1->DR = (u8) ch;
return ch;
}
#endif

#if EN_USART1_RX //èç1ûê1ÄüáË½óêÕ
//′®¿ú1ÖD¶Ï·tÎñ3ìDò
//×￠òa,¶áè¡USARTx->SRÄü±üÃaÄaÃûÆäÃîμÄ′íÎó
u8 USART_RX_BUF[USART_REC_LEN];    //½óêÕ»o3å,×î′óUSART_REC_LEN¸ö×Ö½ú.
//½óêÕ×′ì¬
//bit15￡¬ ½óêÕíê3é±êÖ¾
//bit14￡¬ ½óêÕμ½0x0d
//bit13~0￡¬ ½óêÕμ½μÄóDD§×Ö½úêyÄ¿
u16 USART_RX_STA=0;    //½óêÕ×′ì¬±ê¼Ç[/mw_shl_code]

关山难越 · 发表于 2018-8-29 15:04:27

问题找到了，stm32f4 discovery 这个官网买的开发板串口一倍占用了，我尝试其他串口不行的原因，是我忘了改函数的定义
int fputc(int ch, FILE *f)
{
while((USART2->SR&0X40)==0);//Ñ-»··￠Ëí,Ö±μ½·￠Ëííê±Ï
USART2->DR = (u8) ch;
return ch;
}

我之前改用其他串口不行，就是因为这个USART 没改，发现之后给了自己一巴掌。