1.CUBEMx配置串口的IO口
選擇USART3并配置為Asynchronous?

設置時鐘為216MHz

串口設置為8位數(shù)據(jù),1位停止位

2.生成代碼,并添加串口重定向程序,以便使用printf

3.實驗成功

串口重定向代碼如下
/*-----------------串口重定向 使用printf輸出---------------*/
#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__ */
/**
* @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 EVAL_COM1 and Loop until the end of transmission */
? HAL_UART_Transmit(&huart3, (uint8_t *)&ch, 1, 0x0001);
? return ch;
}
/*-----------------------------------------------------------*/