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spilz
Joined: 30 Jan 2012
Posts: 220
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| printf issue |
 Posted: Wed May 13, 2015 3:55 am |
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Hi everybody
I'm using a PIC18F2550, with PCH V5.015.
I use printf function all the time, and it worked well.
But now my program is big, and i have sometimes issue to print data in a string :
| Code: | typedef signed int32 SINT32;
void test(SINT32 latitude){
char lat[12];
char lat2[12];
sprintf(lat,"%2.6w ",latitude);
sprintf(lat2,"%2.6w ",latitude);
fprintf(DEBUG_UART,lat);
fprintf(DEBUG_UART,lat2);
}
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when my program is short, it works all the time : I have the same string lat and lat2.
But when my program is big (ROM 89% RAM 14%) sometimes I have not the same string...
I guess it comes from the compiler, but I don't know how to solve this.
I have issue too with "strstr(*int8 s1,*int8 s2)" function in the same case.
Did you already experiment this issue?
What solution can I have for that ?
thanks for your help
Spilz |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19553
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| Posted: Wed May 13, 2015 7:53 am |
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Obvious question would be, if you are doing anything else. If (for instance), there is an interrupt running, then a 'memory leak' in it's code, could corrupt a string.
Your format specifiers are wrong, and this can sometimes cause issues with CCS. The number in front of the decimal point on a format specifier, in C, is the _total field width_. You are asking it to put six places after the decimal, in a field that is just two characters wide.....
There is then another problem 'w', only accepts _unsigned_ numbers, not signed.
From the manual:
| Code: |
w Unsigned int with decimal place inserted. Specify two numbers for n. The first is a total field width. The second is the desired number of decimal places.
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spilz
Joined: 30 Jan 2012
Posts: 220
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| Posted: Wed May 13, 2015 8:14 am |
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Hello Ttelmah,
Thanks for your reply,
Sorry for my bad English, I'm not sure to understand :
What I want to do is :
printf latitude which is a signed integer in 10-6 deg, in deg
40123456 -> "40.123456"
-4123456 -> "-4.123456"
According to what you wrote, it shouldn't works for signed, but it does work..
I don't know why.
For the interrupt, actually there are the same in small and big programs, it doesn't explain why it always works in small program and sometime doesn't work in big program...
As with big program there are issues too with other functions with string like strstr(), I guess there is a problem with compiler.
An other point : with the same program (middle size ^^)
I have no issue with
| Code: | char* AT_received;
Main(){
...
AT_received = malloc(250);
...
} |
But I have sometimes issue like above when using :
| Code: | | char AT_received[250]; |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19553
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| Posted: Wed May 13, 2015 8:19 am |
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| 5.015, was a fairly 'early' working V5 compiler. So there might be a problem. You should use an at least 'possible' format specifier. However the compiler will be generating the same code for the print functions, so it does suggest a memory leak. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19553
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| Posted: Thu May 14, 2015 3:47 am |
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I have just checked, and with both that version, and the current versions, it is the use of the signed int32, that causes the problem. As the manual says, %w does not support this. It partially works, but with some values gives garbage results.
I simply tested for the value being -ve, and if it was output a - sign, and then printed the abs value, and it worked fine (though this does give one space between the sign and the number). So it does go back to only using legal specifiers. |
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