Try this…
Insert the card in your nano.
Connect USB
Once the nano is recognised, try and visit via windows explorer, it may ask for a format, I quick formatted with default FAT32
Next you will have to change your folder view properties so that “known file types are unhidden”
Now create a txt file, rename it to FILE002.DAT (seems to be case sensitive)
Now when saving you can save the waveform to the card (well at least I can!)
You can create more of the files via your PC so that you can store many wave forms.
Now all I need is a way to transfer the image from the screen to my PC. I misunderstood and thought this was a feature…