topic PRINTF problem in SDK 2.0 in Kinetis Software Development Kit

PRINTF problem in SDK 2.0

regexp — Sun, 19 Jun 2016 11:22:47 GMT

Hello,

I have FRDM-K64F, KDS 3.2 and SDK 2.0 for K64F CPU family.

When I startet to use SDK 2.0 I found two problem with PRINTF. One less serious is definition of its first parameters "char *", which should be nowadays "const char *". It generates enormous number of warnings.

The second more serious problem is bug of float numbers output. Below is my main():

int main(void) {

/* Init board hardware. */

BOARD_InitPins();

BOARD_BootClockRUN();

BOARD_InitDebugConsole();

float x = 0.9;

printf( "%f %f %f\n", x, x - 1.0, -3.14 );

PRINTF( "%f %f %f\n", x, x - 1.0, -3.14 );

/* Add your code here */

for(;;) { /* Infinite loop to avoid leaving the main function */

__asm("NOP"); /* something to use as a breakpoint stop while looping */

}

The output is:

0.900000 -0.100000 -3.140000

0.900000 -1.100000 -4.140000

The problem is in function DbgConsole_ConvertFloatRadixNumToString where some programmer badly implements condition:

if (fa <= pow(-10, precision_width))

{

intpart--;

}

The sign minus must be in front of pow.

reg.

Re: PRINTF problem in SDK 2.0

DavidS — Mon, 20 Jun 2016 14:10:54 GMT

Hi reg,

printf() is calling compiler tool chain printf.

PRINTF is calling embedded code in KSDK_v2.

PRINTF in KSDK_v2 has errata that the development team is validating currently.

A workaround for it is posted here:

https://community.nxp.com/message/754763?et=watches.email.thread#comment-754763

Regards,

David

Re: PRINTF problem in SDK 2.0

ivadorazinova — Tue, 21 Jun 2016 13:42:26 GMT

Hi,

I recommend what David said. There was a discussion on this topic a few days ago.

Please test it on your side and let us know, if this works you.

Have a nice day.

Iva