I all,

My name is Antonio. I have a problem with standard I\O functions, in particular with sscanf function. I use Free RTOS on SAM7X micro controller compiled with yagarto tool chain (version 4.7.2). The problem is that sometimes the sscanf does not provide in output the values. For example:

char message[32];
int returnScanf;
int getValue;

strcpy(message,"2");

getValue = 5;
returnScanf = sscanf(message,"%d",&getValue);

//returnScanf is equal to 1 (correct), but getValue is equal to 0

It is very strange, because sometimes, if I try to compile again the same source code, it sometimes works properly (without changing any header\compiler option, etc.).

I use this compiler options:

COMPILER_GENERAL_OPTIONS= \
-mthumb-interwork \
-mcpu=arm7tdmi \
-T$(LDSCRIPT) \
-Wall \
-g \
-O1\
-fomit-frame-pointer \
-fno-dwarf2-cfi-asm

and linker options:

LINKER_FLAGS=-nostartfiles -Xlinker -o$(PROJECTNAME).$(ARMEXT) -lm -Xlinker -M -Xlinker -Map=$(PROJECTNAME).$(MAPEXT)

Could you please help me to find the possible mistake?

Thanks in advance

Is your question FreeRTOS related? Is the behaviour the same when executed from main() before the scheduler has started as from a task after the scheduler has started?

Regards.

Hi,

the source code example is inserted inside a FreeRTOS task.