Problems w. division - unsigned long

[Cyberzim]

Hi,
I have a code for a time bar for my mp3-player used on a QVGA color touch screen.
My problem is, when I do the calculation to determine how long I'm in the song, it wont give me any number but 0.
Every variable here is a unsigned long.
I have tested the code, and after I divide 'percent' with 'startsize' I get this bug.
I init the mmc with 'startsize' and transfer the number to 'filesize' afterwards.

Code: Select all

unsigned long percent;

percent = startsize-filesize;
percent *= 2; // Works fine, providing number larger than 0
percent = percent/(startsize/100); // does not work. Only result is zero, no matter for how long time the song is playing.
.....more code.....

And by the way, I have splitted my project in more files so filesize is in another file which is included in the main file. Shouldn't have any affect on the code.

Regards,

Simon H.A.

[slavisa.zlatanovic]

Hi!

I couldn't reproduce the issue you're talking about.
Can you give me a number combination (startsize, filesize) using which when calculated manually
the percent value differs from the value given by compiler in the simulator.

Best regards
Slavisa

[Cyberzim]

Hi Slaviza,
Haven't been able to answer for some time due to Roskilde festival and glandular fever.

I use a number generated from the mmc_fat_reset function. In my testrun, the song had a filesize of 13MB. I'm using 'filesize' with the mmc_fat_reset and then copies the number to startsize so I have a number to calculate the percentage.d
I have discovered more problems with my code. I can't make it stop when the song is finished. I have tried many methos for example checking if 'filesize' is larger or equal to 32 and then return 1 if not. The function won't return 1 at any time.
I can't figure out what I'm doing wrong, if I am doing something wrong.

Regards,

Simon H.A.

[slavisa.zlatanovic]

Hi!

...I use a number generated from the mmc_fat_reset function...

Use function Mmc_Fat_Get_File_Size() to retrieve the size of active file (in bytes).

It would be best that you create a minimal project that depicts the problem you're experiencing.
I must reproduce it and only then I will be able to help you.
You can send your project to my e-mail:
slavisa.zlatanovic@mikroe.com

Best regards
Slavisa

[Cyberzim]

Awesome!
That solved all my problems I had.

Thank you,

Simon H.A.