SPI Interface for MicroSD Card

[Drew7997]

Hello,

I am attempting to mount and write to a microSD card via SPI. I am using the Fat_fs example found under "zephyr/samples/subsys/fs/fat_fs" and I am getting an error code of -5 during disk initialization. 

When I run the same code without the card inserted, I get the exact same behavior. So it almost seems like the driver isn't detecting the card at all. I have check that the sd card is FAT formatted and is working on my computer.

Also when using a logic analyzer, I can see that the MISO, MOSI, CS, and SCK signals appear to be working. However, pretty much all responses from the card (such as the CSD) return empty with all zeros. 

Below is the dts, config, and some notes about the board.

* MISO is tied high by an external resistor. 

Thanks in advance for the help

[Jørgen Holmefjord]

Hi,

Have you tried using a different GPIO for the MISO pin? By default, P0.10 is used for the NFCT peripheral antenna.

If you have not set the Kconfig CONFIG_NFCT_PINS_AS_GPIOS, the NFCT pins may not be used for other purposes or peripherals.

Best regards,
Jørgen

[Drew7997]

Hi Jørgen,

Thank you so much for the suggestion! That fixed the SPI issue and now it is able to detect the board. 

However, mounting the device is still failing. I'm not getting an error code, but it seems like whenever fs_mount is called, main just restarts.

When stepping through the code, I get to this function and the debugger doesn't enter it. As soon as it is called, it just goes back to the top of main.