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Fede Rico
Fede Rico
Associate III
June 15, 2016
Question

No Carrige return when redirect printf() to UART2

  • June 15, 2016
  • 3 replies
  • 1283 views
Posted on June 15, 2016 at 15:41

Hi there,

I'm working on custom board based on STM32F103 and the IDE is Keil. I will use UART2 to print some debug logs. To do this I add the fputc function to my code in order to redirect printf to UART2. 

int fputc(int ch, FILE *f)
{
/* Place your implementation of fputc here */
/* e.g. write a character to the USART */
HAL_UART_Transmit(&uart_debug_handler,(uint8_t*)&ch,1,1);
return ch;
}

Everything work but the output on serial port seems to haven't the Carrige Return (CR). There is only the Line Feed (LF). This is an extract of serial output: 

I'm Alive: 2269
I'm Alive: 2270
I'm Alive: 2271
I'm Alive: 2272

Any suggestions? Thanks a lot! Federico
    This topic has been closed for replies.

    3 replies

    troy1818
    troy1818
    Associate III
    June 16, 2016
    Posted on June 16, 2016 at 10:45

    Do you send /r ?

    Can we see the printf line ?
    Tesla DeLorean
    Tesla DeLorean
    Guru
    June 16, 2016
    Posted on June 16, 2016 at 11:21

    If your terminal needs to receive '' '' when you send ' ', then you are going to have to add that functionality to your fputc() function, or change your terminal settings. 

    int fputc(int ch, FILE *f)
{
/* Place your implementation of fputc here */
/* e.g. write a character to the USART */
if ((char)ch == '
') // LF -> CR LF
HAL_UART_Transmit(&uart_debug_handler,(uint8_t*)''
'',1,1);
HAL_UART_Transmit(&uart_debug_handler,(uint8_t*)&ch,1,1);
return ch;
}

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    Fede Rico
    Fede RicoAuthor
    Associate III
    June 16, 2016
    Posted on June 16, 2016 at 18:18

    Thanks clive1!!!

    You solved my bug in printf!

    Thanks!

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