I figured out why I can’t properly save a bitmap after reading the source code at github.com/Seeed-Studio/DSOQuad … ce/Files.c
Why are you using such a primitive implementation of the FAT file system that doesn’t even support file creation? Is the flash memory space of the STM32 a limitation? It shouldn’t be… I usually use Elm Chan’s FatFs when I need a FAT file system on a microcontroller. It would be super easy for it work with the DSO Quad’s BIOS functions.
Also why not carry a template copy of the bitmap file instead of forcing the user to pre-create it? It’s only a couple of bytes worth of header data.
I don’t even see the document creation process in detail anywhere, but the fact is that the user must create the file in a very exact format first, so I expect this to either be documented very well, or for the code to create the file for you
please download the mannual at viewtopic.php?f=22&t=1929 , there is a detailed declaration about how to save the wave …thanks .
I did read your manual, however, the problem is that the manual never said that the bitmap file must be created in a valid fashion (such that it already contains the bitmap format header that specifies the colour depth and dimension information), and the point of my post is to point out that the firmware can be modified such that this step can be avoided and be more robust.
i am sorry that i did not read you post carefully before my last comment 
as the saving , the designer has told me that the waveform saving will be altered in next firmware version, no need to install a pre-installed file then. as in benf firmware 3.61.
and , i do not know if the designer has any diffculties in achieving such a goal, if you have more detailed suggestions or even decodes for this , it will be helpfull for us.
