I have a 16G microsd that you can see the contents of and it looks like android OS file stuff, but I can't erase or format it. I've tried removing the read only attribute with diskpart and other things with no luck. I read that CMD27 can set or clear bits related to write protection, but I don't see any info about this. Has anyone else run into this and know of a tool that resets the card so it can be written to again? I've got a project going with fatfs on AVR so I can sent commands to it if I just knew the right one to send.