NRF52

[micheld_]

I'm actually building a project that need to communicate with sdcard.

i read a lot about that and i'm very confusing when i passed on nordic sdk lot of code and ressources lot of files speaking about the same things: NRFx_SPI , NRF DRV SPI ...

Can you give me a NRF52-pca10056 basic example with write and read a block of data from a sdcard no need of any fatfs lib or other complicated code.

Thanks,

Reagards.

[Jørgen Holmefjord]

Hi,

We only provide the FatFs example for reading/writing SD Cards. Most customers would like a file-system for their cards and then this example makes sense. If you do not want to use this library, I guess you can use the SPI example as a starting point for your application, but you will have to read the SD Card specifications yourself to find the appropriate SPI commands to read and write blocks from/to the SD Card. We do not provide any ready-made examples that do this.

Best regards,
Jørgen

[Jørgen Holmefjord]

You may reference the SD card library documentation. It gives a short description of how the library can use used.

SPI Master example uses the legacy driver API (nrf_drv_spi). This driver API combines support for both SPI and SPIM (EasyDMA support) peripheral. The legacy API uses the NRFX drivers in the bottom, it is just a middle-layer adapting the API to support the old example implementations.

nrfx SPI Master example uses the nrfx_spim driver API directly. This example was added since instance SPIM3 (High Speed SPI - 32 MHz) available on nRF52840 is not supported in the legacy API driver.

[micheld_]

Thank you for your feedback.

1- Can you gives a more complete sample to build the SD card library?

2- When APP_SDCARD_SPI_INSTANCE is activated in sdk_config.h with one will be used (nrf_SPI of nrfx_SPI?)

   is there other more configuration to set if i want to use DMA with SPI?

Best regards

[Jørgen Holmefjord]

micheld_ said:

1- Can you gives a more complete sample to build the SD card library?

Unfortunately, we only have the FatFs example showing the usage of this library. app_sdcard is used through nrf_block_dev_sdc which interfaces with FatFs through Nordic's port layer (diskio_blkdev).

micheld_ said:

2- When APP_SDCARD_SPI_INSTANCE is activated in sdk_config.h with one will be used (nrf_SPI of nrfx_SPI?)

This will depend on the configuration of the SPI driver (nrf_drv_spi). If EasyDMA for the corresponding instance is enabled, EasyDMA will be used:

// <q> SPIx_USE_EASY_DMA  - Use EasyDMA
 
#ifndef SPIx_USE_EASY_DMA
#define SPIx_USE_EASY_DMA 1
#endif

[micheld_]

Thanks for support.

I think it is better that nordicsemi can provide an example based on sdcard like STMicroelectrics on stm32 tagret, I hope I would not go to them.

Best regards.