RTOS/CC2640: sprintf issue using float format

Dilbert K

Expert 1210 points

Part Number: CC2640

Tool/software: TI-RTOS

I am using the TI-SDK ble_sdk_2_02_01_18 release on CC2640.

When I tried to convert a float into string for print out, the system will crash.

I created the test code as below, function will never return.

However, if I use "%6d" instead, function will return just fine.

I had already checked suggestion which

#include <stdio.h> is there
increase the stack size from 700 to 1000

void test1(float value)
{
char buf[50];

sprintf(buf, "%.4f", value);
// sprintf(buf, "%f", value);
// sprintf(buf, "%6d", (int)value);

System_printf(buf);
System_printf("\n");System_flush();
}

Thanks for advice and suggestions

over 8 years ago

0 Alan DeMars over 8 years ago

TI__Mastermind 30830 points

sprintf uses a very large amount of stack memory. Try increasing the size of the stack in the task that is calling sprintf.
Is there a reason you're not using System_sprintf()? It is designed specifically to use less stack memory.

Alan

0 Dilbert K over 8 years ago in reply to Alan DeMars

Expert 1210 points

Do you have idea how much stack space I may need to increase ? ~500 ~1000 bytes ?

I am using the sprintf function to convert a float into ASCII text and send to other device.

So, not just for debug display.

0 Alan DeMars over 8 years ago in reply to Dilbert K

TI__Mastermind 30830 points

My past experience using sprintf() revealed that it used around 500 bytes of stack.

You can use the equivalent "System_sprintf()" function which should significantly reduce the stack burden.

Alan

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RTOS/CC2640: sprintf issue using float format