I have some hardware outputting data to a MicroSD. I can't control this process and instead of it outputting data to a MicroSD, I want some sort of spoofer I can insert into the MicroSD slot that allows the data sent to the microSD to be intercepted by, say, a microcontroller, who in turn saves it on its own microSD.
I have found this piece of hardware, which I feel is somewhat in the direction of the solution I'm looking for. The problem now is with spoofing the filesystem of MicroSD's so the hardware thinks it has a regular microSD inserted.
To what extent is this possible? It comes off as fairly straightforward to me, but I'm sure I haven't foreseen many issues. My idea is that I just hook up the breakout to pins on a Raspberry and get it over with. I'm pretty sure the hardware checks for a valid formatted storage first, but that's what the extra card slot is for. Effectively I'm duplicating the data this way.
I haven't found much information on the internet on this topic.
Similar question: https://stackoverflow.com/questions/13699203/sd-card-emulator