CubeMx——串口与 printf 打印

CubeMx 配置

fputc 实现

/* USER CODE BEGIN 0 */
#include <stdio.h>
/* USER CODE END 0 */

/* USER CODE BEGIN 1 */
int fputc(int ch, FILE *f)
{
    /* Place your implementation of fputc here */
    /* e.g. write a character to the USART */
    uint8_t send_data = ch;
    HAL_UART_Transmit(&huart1, &send_data, 1, HAL_MAX_DELAY);

    return ch;
}
/* USER CODE END 1 */

使能 libc

编译报错解决

• Undefined symbol use two region memory (referred from startup stm32xxx)
• Undefined symbol initial sp (referred from entry2.o)

解决这两个错误也 比较简单，在 .s 启动文件中将 Stack_Size 改大一点就可以了

Stack_Size		EQU     0x600

或者直接在 CubeMx 生成的时候修改配置

串口打印

/* USER CODE BEGIN PV */
#include <stdio.h>
/* USER CODE END PV */

  /* USER CODE BEGIN 2 */
  printf("this is printf example\r\n");

  /* USER CODE END 2 */