jie zhao

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9 years, 11 months ago.

printf cannot be used in RawSerial class in LPC1549

Dear,

I am trying to use RawSerial to output debug information. I delcare debug serial port as RawSerial class, the system will halt when printf is called, such as RawSerial pc(D1, D0); pc.printf("hello world.\r\n")

I delcare debug serial port as Serial class, the system will work well when printf is called, such as Serial pc(D1, D0); pc.printf("hello world.\r\n")

Does the printf is supported in RawSerial class in LPC1549 platform?

Thanks.

Question relating to:

Last updated: 30 Mar 2019

1 Answer

Toyomasa Watarai
9 years, 8 months ago.

Hi,

The RawSerial::printf() calls vsnprintf() function to get string length and ARM microlib of online compiler doesn't seem to fully support some of ISO C functions which LPC1549 target build use. https://mbed.org/users/mbed_official/code/mbed-src/file/17565898c031/common/RawSerial.cpp

You can use puts() function instead of printf() for RawSerial class.

RawSerial pc(D1, D0);
char tmp[80];
sprintf(tmp, "hello world.\r\n");
pc.puts(tmp);

I hope this helps.

Cheers, Toyo

Accepted Answer