Is there a Library connect MicroSDHC via SPI

[nRF52_DK_usr]

Hi,

i want/need to connect & access a microSD Card (32GB) on an breakout board via SPI (technical reasons) and want to use the suggested PINS (28-31) as in the intermediate lesson 5 exercise 1.

Is there a separate library (except the described spi, gios, devicetree) available/required, like an SD.h?

Thanks for hints/suggestions

[Kazi Afroza Sultana]

Hello,

''Is there a separate library (except the described spi, gios, devicetree) available/required, like an SD.h?''

There is no separate Arduino-style SD.h-like library for NCS. 

As you are on dev academy intermediate course (lesson 5 exercise 1), so you know how to enable SPI and GPIO over the driver. You have to enable the follwoing config in prj.conf file

CONFIG_GPIO=y
CONFIG_SPI=y

You can add sd card following way (https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/services/storage/disk/access.html#sd_card_support_via_spi)

&spi1 {
    status = "okay";
    cs-gpios = <&gpio0 27 GPIO_ACTIVE_LOW>;  /* example CS pin */

    sdhc0: sdhc@0 {
        compatible = "zephyr,sdhc-spi-slot";
        reg = <0>;
        status = "okay";

        mmc {
            compatible = "zephyr,sdmmc-disk";
            disk-name = "SD";
            status = "okay";
        };

        spi-max-frequency = <24000000>;
    };
};

For the nRF5SDK. there is SD card library that communicates SD over SPI (nRF5 SD card lib) but not on NCS.

Thanks.

BR

Kazi

[nRF52_DK_usr]

Hi,

ok, i assumed it, but thanks for the suggestion. Compiling works, initialization of the microSD not yet.

But what means NCS?

[Kazi Afroza Sultana]

Hello,

NCS means nRF Connect for SDK.

''Compiling works, initialization of the microSD not yet.''

Can you show me the board files?

[nRF52_DK_usr]

// nrf52dk_nrf52832.overlay:

&spi0 { status = "disabled";};

&i2c1 { status = "disabled";};

&spi1 {

/* What about this property?? */

//compatible = "nordic,nrf-spi";//using SPI as per ERRATA 58

status = "okay";

pinctrl-0 = <&spi1_default>;

pinctrl-1 = <&spi1_sleep>;

pinctrl-names="default", "sleep";

cs-gpios = <&gpio0 31 GPIO_ACTIVE_LOW>;

sdhc0: sdhc@0 {

compatible = "zephyr,sdhc-spi-slot";

status = "okay";

reg = <0>;

mmc {

compatible = "zephyr,sdmmc-disk";

status = "okay";

disk-name = "MMC SD";

};

spi-max-frequency = <24000000>; //max frequency up to 25MHZ

};

};

/* Change the pin configuration */

&pinctrl{

spi1_default: spi1_default{

group1{

psels=<NRF_PSEL(SPIM_SCK, 0, 28)>,

<NRF_PSEL(SPIM_MOSI, 0, 29)>,

<NRF_PSEL(SPIM_MISO, 0, 30)>;

};

};

spi1_sleep: spi1_sleep{

group1{

psels=<NRF_PSEL(SPIM_SCK, 0, 28)>,

<NRF_PSEL(SPIM_MOSI, 0, 29)>,

<NRF_PSEL(SPIM_MISO, 0, 30)>;

low-power-enable;

};

};

};

[Kazi Afroza Sultana]

Hello,

Try to set SPI max frequency 400 kHz

spi-max-frequency = <400000>;

The overlay file based on your overlay be like this:

&spi1 {
    compatible = "nordic,nrf-spim";   /* enable SPIM driver */
    status = "okay";
    pinctrl-0 = <&spi1_default>;
    pinctrl-1 = <&spi1_sleep>;
    pinctrl-names = "default", "sleep";
    cs-gpios = <&gpio0 31 GPIO_ACTIVE_LOW>;

    sdhc0: sdhc@0 {
        compatible = "zephyr,sdhc-spi-slot";
        reg = <0>;
        status = "okay";
        spi-max-frequency = <400000>; /* start low */

        mmc {
            compatible = "zephyr,sdmmc-disk";
            status = "okay";
            disk-name = "MMC SD";
        };
    };
};