CubeMx 配置

fputc 實現

/* 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

編譯報錯解決

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

解決這兩個錯誤也 比較簡單，在 .s 啟動文件中將 Stack_Size 改大一點就可以了

Stack_Size		EQU     0x600

或者直接在 CubeMx 生成的時候修改配置

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 */