RTOS: Printf of hexdecimal not works

Mark Felberg

Guru 19990 points

Tool/software: TI-RTOS

Hi, I'm working with the serial and I'm having trouble printing a hexadecimal value in uppercase. In lower case it works very well, in fact, I have:

System_sprintf(value, "%02x %02x %02x %02x\n ", Myvar[0], Myvar[1], Myvar[2], Myvar[3]);
	    UART_write(uart, value, 29);

And I see: 5e 5e 5e 5e

If I use:

System_sprintf(value, "%02X %02X %02X %02X\n ", Myvar[0], Myvar[1], Myvar[2], Myvar[3]);
	    UART_write(uart, value, 29);

I see: X X X X

Why?

over 4 years ago

0 YiKai Chen over 4 years ago

Guru 735455 points

I remember I had told not to use System_printf and UART_write at the same time.

0 Mark Felberg over 4 years ago in reply to YiKai Chen

Guru 19990 points

If I use only System_sprintf it is the same thing. But you didn't answer my question

0 YiKai Chen over 4 years ago in reply to Mark Felberg

Guru 735455 points

I had told you to use sprintf to format hex values to a string buffer and use System_printf to print the buffer.

0 Mark Felberg over 4 years ago in reply to YiKai Chen

Guru 19990 points

I'm doing as you said, but still not printing hex in Upper case. Why do you still not answer my question?

0 YiKai Chen over 4 years ago

Guru 735455 points

In C language, lower case “x” in sprintf means to be replaced by the value in hex and upper case “X” in sprintf means to print upper case “X” directly.

0 Mark Felberg over 4 years ago in reply to YiKai Chen

Guru 19990 points

I try but not works. In C language to printf a hex value with two value (f.e 6e), you should to need of use %02x in lower case and upper case "%02X" but this not works, I see only X.

0 YiKai Chen over 4 years ago in reply to Mark Felberg

Guru 735455 points

What do you try but not work?

0 ToddMullanix over 4 years ago in reply to YiKai Chen

TI__Guru* 96960 points

Hi Mark,

Capital X is not supported in System_printf. Here are the supported ones

CONVERSION SPECIFIERS

The following conversion specifiers are supported.

d, i: signed integer
u: unsigned decimal
x: unsigned hex
o: unsigned octal
p: pointer (@ + hex num)
c: character
s: string

EXTENDED CONVERSION SPECIFIERS

The following conversion specifiers are optionally supported. See the extendedFormatsconfiguration parameter for more information about how to enable these conversion specifiers.

f: decimal floating point.
$: non-ANSI conversion prefix. This prefix indicates that the next character identifies a non-ANSI standard conversion. See the next section for details.

NON ANSI CONVERSION SPECIFIERS

Among the extended conversion specifiers are unique specifiers which are not part of ANSI printf. These are specified using a $, for example %$L.

These unique specifiers do not support the minimum field width attribute. Certain specifiers have additional restrictions; see below.

'$L': The argument is treated as a pointer to a Types.Label and is converted to an appropriate string.
'$F': Displays a file and line number; used for displaying the call site. This specifier consumes two arguments, the file and line number, in that order. See an example below.
'$S': The argument is treated as a format string, and is recursively formatted using any following arguments. This specifier does not support the use of the "precision" field for specifying maximum string length.

Take a look at the cdoc for the xdc.runtime.System module for more details.

Todd

0 Mark Felberg over 4 years ago in reply to ToddMullanix

Guru 19990 points

Then I can't to use the X to see the hex value in uppercase?

0 YiKai Chen over 4 years ago in reply to Mark Felberg

Guru 735455 points

I doesn’t work in this way.

0 ToddMullanix over 4 years ago in reply to YiKai Chen

TI__Guru* 96960 points

Mark,

Correct. 'X' is not supported.

Todd

Sub-1 GHz

Sub-1 GHz forum

RTOS: Printf of hexdecimal not works