SD Card And NRF52832

[Anar]

Hello. I have a breakout board (SMARTMP3 VS1053) and it has also a slot for memory card, so I connect the wires (SCK, MOSI, MISO and CS) to my nrf52832, but it can't see the memory card (i'm using the FATFS example). However, when I connect directly SD CARD with wires to nrf52832 it works fine.

[Jørgen Holmefjord]

Hi, 

Your board have a TXB0106 Voltage-Level Translator to support 5V signals from Arduino and other platforms. If you have set the board in 5V mode (Jumper J1), the VCC input of port B of the level translator is most likely connected to 5V. The specifications say Logic High Signal is minimum 0.65 x VCC = 0.65 x 5V = 3.25V. The GPIOS of the nRF52832 might not provide this level. On our DK it is usually between 2.8 and 3.0V.

Have you cheked the position of the jumper, and could you try setting it to 3.3V if it was set to 5V?

Best regards,
Jørgen

[Jørgen Holmefjord]

I would recommend that you check the voltage levels of the outputs of the U3 IC according to the schematics, to make sure it is within acceptable range for the SD card.

Since the example is working when you connect it to the SD card directly, there is no issue on the nRF chip. The issue must be with the board where the SD card slot is mounted. 

[Anar]

Yeah, I know that the issue must be with the board, but is there solution for this?

[Jørgen Holmefjord]

I gave you some suggestions on checking the voltage levels. Did you do this? Otherwise you need to contact the developers of the board and ask for details on how to use the SD card slot with external 3.3V devices. 

[Anar]

Yeah, I have almost solved this problem.

Can I also ask you one more question?
How can I use fatfs example and spi peripheral in one project? (The same pins and instance)
Because when I try to use SPI functions (like transfer) after the disk (sd card) initializing it gives me error and reset.