RA MCU 生態工作室致力于構建一個完善的 RA 生態，這將會是一個好玩有趣的開放社區，也提供各種RA相關問題的解決方法。

1.概述

通過RASC創建一個串口工程，具體配置如下，用戶可以根據自己定義來配置串口相關的基本參數。

2.創建工程

STEP1：RASC創建工程

STEP2：選芯片型號跟IDE類型

STEP3：選擇芯片型號

STEP4：選擇無操作系統

STEP5：勾選確認工程

STEP6：配置串口號跟IO口

STEP7：添加串口驅動

STEP8：配置串口

STEP9：配置串口基本屬性

STEP10：生成工程

3.代碼

STEP11：打開工程

STEP12：添加代碼

STEP13：具體代碼如下

void hal_entry( void )
{
    /* TODO: add your own code here */
    fsp_err_t err = R_SCI_UART_Open( &g_uart9_ctrl, &g_uart9_cfg );
    assert( FSP_SUCCESS == err );
    while ( true )
    {
        printf( "Hello RA MCU \r\n" );
    }
#if BSP_TZ_SECURE_BUILD
    /* Enter non-secure code */
    R_BSP_NonSecureEnter();
#endif
}

STEP14：添加頭文件跟串口回調函數

STEP15：具體代碼如下

#include "hal_data.h"
#include "stdio.h"
FSP_CPP_HEADER
void R_BSP_WarmStart( bsp_warm_start_event_t event );
FSP_CPP_FOOTER
uint8_t g_transfer_complete = 0;
void g_uart9_cb( uart_callback_args_t* p_args )
{
    /* Handle the UART event */
    switch ( p_args->event )
    {
        /* Received a character */
        case UART_EVENT_RX_CHAR:
        {
            break;
        }
        /* Receive complete */
        case UART_EVENT_RX_COMPLETE:
        {

            break;
        }
        /* Transmit complete */
        case UART_EVENT_TX_COMPLETE:
        {
            g_transfer_complete = 1;
            break;
        }
        default:
        {
        }
    }
}

STEP16：添加打印接口重定向代碼，具體如下

/*******************
 *
 * Copyright 1998-2017 IAR Systems AB.
 *
 * This is a template implementation of the "__write" function used by
 * the standard library.  Replace it with a system-specific
 * implementation.
 *
 * The "__write" function should output "size" number of bytes from
 * "buffer" in some application-specific way.  It should return the
 * number of characters written, or _LLIO_ERROR on failure.
 *
 * If "buffer" is zero then __write should perform flushing of
 * internal buffers, if any.  In this case "handle" can be -1 to
 * indicate that all handles should be flushed.
 *
 * The template implementation below assumes that the application
 * provides the function "MyLowLevelPutchar".  It should return the
 * character written, or -1 on failure.
 *
 ********************/

#include 

#pragma module_name = "?__write"

int MyLowLevelPutchar(int x)
{
  R_SCI_UART_Write(&g_uart9_ctrl, (uint8_t *)&x, 1);
  while(g_transfer_complete == 0); 
  g_transfer_complete = 0;
  return x;
 
}

/*
 * If the __write implementation uses internal buffering, uncomment
 * the following line to ensure that we are called with "buffer" as 0
 * (i.e. flush) when the application terminates.
 */

size_t __write(int handle, const unsigned char * buffer, size_t size)
{
  /* Remove the #if #endif pair to enable the implementation */
#if 1

  size_t nChars = 0;

  if (buffer == 0)
  {
    /*
     * This means that we should flush internal buffers.  Since we
     * don't we just return.  (Remember, "handle" == -1 means that all
     * handles should be flushed.)
     */
    return 0;
  }

  /* This template only writes to "standard out" and "standard err",
   * for all other file handles it returns failure. */
  if (handle != _LLIO_STDOUT && handle != _LLIO_STDERR)
  {
    return _LLIO_ERROR;
  }

  for (/* Empty */; size != 0; --size)
  {
    if (MyLowLevelPutchar(*buffer++) < 0)
    {
      return _LLIO_ERROR;
    }

    ++nChars;
  }

  return nChars;

#else

  /* Always return error code when implementation is disabled. */
  return _LLIO_ERROR;

#endif

}

4.工程配置

STEP17：工程配置

STEP18：彈出如下窗口

5.結果

STEP19：接上串口工具，打印如下

投稿：欣瑞利科技@Moxair