嵌入式开发串口printf重定向实现方法

方法一 重写fputc

int fputc(int ch, FILE *f)
{
  HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xffff);
  return ch;
}

记得添加#include "stdio.h"头文件

方法二

#include "stdarg.h"
#include "stdio.h"


int UART_printf(UART_HandleTypeDef *huart, const char *fmt, ...) {
    va_list ap;
    va_start(ap, fmt);
    int length;
    char buffer[128];
    length = vsnprintf(buffer, 128, fmt, ap);
    HAL_UART_Transmit(huart,buffer,length,HAL_MAX_DELAY);//HAL_MAX_DELAY
//    CDC_Transmit_FS((uint8_t*)buffer,length);
    va_end(ap);
    return length;
}