调试的时候很多时候用到串口 这里教你怎么样使用Printf 函数 
 
在程序中添加Printf.txt
1,
#include
2,
/* Private functions ---------------------------------------------------------*/ 下添加
 
void USART_Configuration(void);
 
#ifdef __GNUC__
/* With GCC/RAISONANCE, small printf (option LD Linker->Libraries->Small printf
     set to 'Yes') calls __io_putchar() */
#define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
#else
#define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
#endif /* __GNUC__ */
 
3，添加如下2个函数 usart配置 和 重定向 C库的printf函数
void USART_Configuration()
{
/* USARTx configured as follow:
        - BaudRate = 9600 baud 
        - Word Length = 8 Bits
        - One Stop Bit
        - No parity
        - Hardware flow control disabled (RTS and CTS signals)
        - Receive and transmit enabled
*/
USART_InitTypeDef USART_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;
/* Configure USART1 Tx (PA9) as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOA, &GPIO_InitStructure);
 
/* Configure USART1 Rx (PA10) as input floating */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOA, &GPIO_InitStructure);
 
 
USART_InitStructure.USART_BaudRate = 9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
 
USART_Init(USART1, &USART_InitStructure);
/* Enable USART1 */
USART_Cmd(USART1, ENABLE);
}
 
/**
* @brief Retargets the C library printf function to the USART.
* @param None
* @retval None
*/
PUTCHAR_PROTOTYPE
{
/* Place your implementation of fputc here */
/* e.g. write a character to the USART */
USART_SendData(USART1, (uint8_t) ch);
 
/* Loop until the end of transmission */
while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET)
{}
 
return ch;
}
4，
 
void RCC_Configuration(void) 添加 
/* Enable GPIOA and USART1 clocks */
   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_USART1, ENABLE);
5,
STM32F10x.CONF.H 
 
去掉/* #include "stm32f10x_usart.h" */ 的注释
6，
在Main()中添加
 
void USART_Configuration()
 
然后就可以在main（）调用 
 
printf("The is a example!" );
 
 
printf("%s%c%c%c%c%c%s",
           "#**",
           Value/256,Value%256,
          '&',
           Value_2/256,Value_2%256,
          "**%");
 
之类的输出函数

看不懂！