Bill Greiman

The FsFile and SdFs classes support FAT16/FAT32 and exFAT. RingBuf is a template that supports any file class. for exFAT only use ExFile and SdExFat like this. ``` SdExFat sd;...

Never format a 512MB SD FAT32. They are designed for FAT16. Use the [SdFormatte](https://github.com/greiman/SdFat/blob/master/examples/SdFormatter/SdFormatter.ino)r example or the SD Association f[ormatter](https://www.sdcard.org/downloads/formatter/) for the standard format which will optimize performance and reliability.

There are many custom formats and partition layouts used for SD cards but SdFat only supports the SD association standard format for SD cards. SD card hardware internals and firmware...

To zero the first sector just add the following to the above example. ``` memset(buf, 0, 512); if (!card.writeSector(0, buf)) error("card.writeSector"); ``` After this the MBR sector will be entirely...

I just noticed the card is GPT. The MBR is not used. It is just [protective](https://en.wikipedia.org/wiki/GUID_Partition_Table#Protective_MBR_(LBA_0)). Did you try the SdFormatter example with the 'E' option. It uses the hardware...

SD cards can be write protected. SD stands for Secure Digital. Cards can protect their contents from erasure or modification, prevent access by non-authorized users, and protect copyrighted content using...

You may be able to save the card if simple write protection was used. https://www.diskpart.com/articles/remove-write-protection-on-micro-sd-card-sandisk.html You will need a utility like the AOMEI Partition Assistant. Maybe you formatted the card...

The card was definitely formatted as internal in an Android device. I went back and found this earlier in your post. > Number Start End Size File system Name Flags...

You can see why I have avoided using any of the mysterious "Secure Digital" features of cards. Some users have asked for this. I don't even support an API for...

Don't blame the SD-Card manufacturer - DRM was never intended for this use. Looks like Samsung allows encrypted filesystems on SD cards but does not use the new ASSD features...