So I use a uSD card on my board for my photon & electron devices with the SDFat library. I connect it with the standard SPI (not SPI1) pins. Everything works fine with my Electrons and Photons on the given board (and has for a long time) - they can use the SD card fine. The SD Card holder is soldered on the board with very short traces to the Particle device pins, and no other external components.
However, using an Argon via the Classic Adapter, the sd.begin() call fails, with error code: 0x20, 0x00 (with normal SPI), or 0x20, 0xFF (with SoftwareSpi). This is using the bench example from the SDFat library (using version 1.0.16).
Has anyone else successfully used an SD card with the Classic Adapter, especially with SDFat? Is there anything specific I should try or check for on the hardware level? I don’t have a ton of low-level experience with SPI or SD Cards, so while I could mess around, I’m sure someone may have some specific suggestions.