Using SD card on nRF9161 DK

RE: Using SD card on nRF9161 DK

AHaug — Tue, 08 Jul 2025 09:39:46 GMT

Noted,

I can't promise anything but I will see if I can get it compiling. But yeah, since I guess both Edvin and I missed that fact that there's no USB controller, then the best way might still be to base it on the usb/mass implementation and dissect out the USB parts and implement the SPI solution in the resources I posted.

There's no other samples that might be working as a foundation within the SDK.

Kind regards,
Andreas

RE: Using SD card on nRF9161 DK

JOEBRE — Tue, 08 Jul 2025 08:47:05 GMT

No, as stated initially, I just need to have SD card running with LittleFS on my application. My initial starting point was the format sample ... which was building and running correctly on nRF9161 target with exception of the LittleFS stuff ... then Edvin told me to use the mass sample as starting point and build it for nRF9161... I personally just need the SD card working on whatever sample which is buildable for the nRF9161 target.

Joel

RE: Using SD card on nRF9161 DK

AHaug — Tue, 08 Jul 2025 08:37:55 GMT

Happy to help,

[quote user="JOEBRE"]It remains unclear to me how this particular example can successfully build for a nRF9161 target which do not has a USB controller on chip. [/quote]

Hmm... If you aim to use the SD card through USB in any ways, I guess the answer is that it won't work, but if you intend to use the SD card through SPI only as shown in some of the links below it should work. The usb/mass sample is a Zephyr sample that intends to show both how to use it as a USB storage device (and thus also with the SD card overlay to be used as something where you can load/unload data to the SD card with USB), whereas the SPI SD card configuration is just to set up an SPI communication to read/write to the SD card. That's at least how I understand it.

You may find some more information on the Zephyr discord forums w.r.t this sample. Since it's a Zephyr sample, the support for the sample is somewhat limited (such as it not building out of the box due to that nRF Connect SDK uses Partition Manager and Zephyr does not).

Kind regards,
Andreas

RE: Using SD card on nRF9161 DK

JOEBRE — Tue, 08 Jul 2025 07:56:28 GMT

Many thanks for the detailed procedure... It remains unclear to me how this particular example can successfully build for a nRF9161 target which do not has a USB controller on chip.

Joel

RE: Using SD card on nRF9161 DK

AHaug — Mon, 07 Jul 2025 15:57:57 GMT

Hi Joel,

Edvin is out of office on PTO so I'll be handling this case for this week (lets hope we can resolve it by Friday before I also leave for PTO..).

If I understand you correct, what you're missing now is to port the solution so that it works on a 9161dk, right?

If so, then what we're missing should be the following.

You're correct that this specific configuration maps to the SPI flash, which is due to the nRF52840DK not having a SD card reader on board so it requires the additional hardware mentioned in the build command here:

But lets stick to making this sample work for the nRF9160DK before we look into the SD card implenation (divide and conquer the problem).

It also mentions the additional config in the last build argument and since you're working with NCS, you still need to have a pm_static.yml for your partitioning as well as an overlay tailored to the board you're using, which brings us to the last problem.

Edvin says that you can copy the nrf52840 related overlay and rename it for the board you're building for, which is correct, but you also have to make a modification to the external flash device that you're using. The nRF9161 uses the GD25WB256 flash, which you can see in an overlay file here: https://github.com/NordicDeveloperAcademy/ncs-inter/blob/main/l9/l9_e3_sol/spi/app_gd.overlay and/or in any cellular samples in nrf/samples where the external flash is enabled or the board files within zephyr/boards/nordic/ in the SDK.

I.e change your overlay (which should be) for

nrf52840dk_nrf52840.overlay:

/*
 * Copyright (c) 2019 Peter Bigot Consulting, LLC
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/delete-node/ &storage_partition;

&mx25r64 {
	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		storage_partition: partition@0 {
			label = "storage";
			reg = <0x00000000 0x00020000>;
		};
	};
};

/ {
	msc_disk0 {
		compatible = "zephyr,flash-disk";
		partition = <&storage_partition>;
		disk-name = "NAND";
		cache-size = <4096>;
	};
};

nrf9160dk_nrf9160.overlay (or the target you're building for as listed:

and do something like (I've merged the app_gd.overlay and the 52840 overlay, there might be something wrong so check when building if it behaves as expected)

/*
 * Copyright (c) 2019 Peter Bigot Consulting, LLC
 *
 * SPDX-License-Identifier: Apache-2.0
 */

/delete-node/ &storage_partition;

&gd25wb256 {
	status = "okay";
};

/ {
	chosen {
		nordic,pm-ext-flash = &gd25wb256;
	};
};


&gd25wb256 {
	partitions {
		compatible = "fixed-partitions";
		#address-cells = <1>;
		#size-cells = <1>;

		storage_partition: partition@0 {
			label = "storage";
			reg = <0x00000000 0x00020000>;
		};
	};
};

/ {
	msc_disk0 {
		compatible = "zephyr,flash-disk";
		partition = <&storage_partition>;
		disk-name = "NAND";
		cache-size = <4096>;
	};
};

After we've succeeded with this, we should have a emulated SD card in SPI external flash for the 9161DK which is good, because now we now that the sample works and compiles for the nRF9160DK and we can exclude quite a bit of uncertainties.

The next task is to port it to an SD card.

To do this we need some more modifications (or additional hardware). "west build -b nrf52840dk/nrf52840 --shield waveshare_epaper_gdeh0154a07 samples/subsys/usb/mass -- -DCONFIG_APP_MSC_STORAGE_SDCARD=y" handles the extra hardware since it uses a shield that has an SD card reader, and it adds the extra configuration.

In addition https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/samples/subsys/usb/mass/README.html#sd_card_example takes us to modifications that you need to do yourself, i.e https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/services/storage/disk/access.html#disk-access-api and to add a SPI (I assume that this is the peripheral you will be using) that can do SD card https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/services/storage/disk/access.html#disk-access-api. An example can be seen in the latter link for how to set this up:

&spi1 {
        status = "okay";
        cs-gpios = <&porta 27 GPIO_ACTIVE_LOW>;

        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>;
        };
};

Kind regards,
Andreas

RE: Using SD card on nRF9161 DK

JOEBRE — Mon, 07 Jul 2025 06:40:18 GMT

Ok, of course this makes the sample building with success ... but nrf52840dk_nrf52840.overlay maps storage_partition onto the mx25r64 serial SPI flash ... not to the SD card .

Which changes are needed to set storage_partition being pointing to the SD card ?

Joel

RE: Using SD card on nRF9161 DK

Edvin — Sat, 05 Jul 2025 22:15:43 GMT

You need to copy the nrf52840-related overlay file and rename it for the board you are building for (nrf9161dk_nrf9161_cpuapp.overlay).

Best regards,

Edvin

RE: Using SD card on nRF9161 DK

JOEBRE — Thu, 03 Jul 2025 15:04:51 GMT

Hello... I'm a little confused ... mass storage example is building with success when i set nrf52840dk/nrf52840 as board (which has its dt overlay under boards).

west build -b nrf52840dk/nrf52840 -d build -- -DCONFIG_APP_MSC_STORAGE_SDCARD=y is ok

If I set nrf9161dk/nrf9161 the build ends with errors ...

west build -b nrf9161dk/nrf9161 -d build -- -DCONFIG_APP_MSC_STORAGE_SDCARD=y fails

C:/ncs/v3.0.2/zephyr/samples/subsys/usb/mass/src/main.c:36:2: error: #error No supported disk driver enabled
36 | #error No supported disk driver enabled

Joel

RE: Using SD card on nRF9161 DK

Edvin — Thu, 03 Jul 2025 12:44:36 GMT

It shouldn't matter whether it is an nRF9161DK or nRF52840DK when it comes to SD card.

Or did I misunderstand you?

Best regards,

Edvin

RE: Using SD card on nRF9161 DK

JOEBRE — Thu, 03 Jul 2025 05:34:37 GMT

Ok, unfortunately I do not have an nRF52840DK board. I just have a nRF9161DK and the sample do not builds for this target, it is therefore impossible for me to follow your advice.

Regards, Joel

RE: Using SD card on nRF9161 DK

Edvin — Wed, 02 Jul 2025 21:18:05 GMT

I am sorry, but I have not played around too much with SD cards in Zephyr/NCS. Did you test it? Does it actually use the SD card?

I would test it, but we are very limited on resources right now, due to summer holiday season in Norway, and I don't think I will be able to set aside the time to test it before leaving in two days.

If there is no SPI activity on the SD card gpios, can you compare the behavior with NCS v2.6.X? There the sample built without any modifications. Alternatively, you can reach out to the Zephyr support forum, as the SD card library is really not maintained by Nordic Semiconductor.

Or, I can have a look when I return in end of July. I am terribly sorry for the inconvenience!

Best regards,

Edvin

RE: Using SD card on nRF9161 DK

JOEBRE — Wed, 02 Jul 2025 08:59:29 GMT

Hello, thanks... this explains a lot of things... with your input I'm now able to build LittleFS for nRF52840 too.

Question about the pm_static.yml you provided ... doesn't "region: flash_primary" means that you're placing the storage_partition into the main flash instead of the desired external SD flash ?

I tried the format sample by substituting LittleFS with FAT_FILESYSTEM_ELM and it is working perfectly using "SD:"as ID ... the issue is related to the usage of LittleFS.

Joel

RE: Using SD card on nRF9161 DK

Edvin — Tue, 01 Jul 2025 13:46:03 GMT

Hello,

Yes, I noticed that now. It built fine before v2.7.0, when sysbuild was introduced. Since it is in the zephyr part of NCS, we do not have direct control over these samples, so not all of them work out of the box.

I got it running for the nRF52840 DK by adding this pm_static.yml file to the application folder:

storage_partition:
  affiliation: disk
  extra_params: {
      disk_name: "littlefs",
      disk_cache_size: 4096,
      disk_sector_size: 512,
      disk_read_only: 0
    }
  address: 0xfa000
  end_address: 0x100000
  placement:
    before:
    - end
  region: flash_primary
  size: 0x6000

(I was not allowed to upload .yml file, but you can take this one, and rename it "pm_static.yml"

devzone.nordicsemi.com/.../4578.pm_5F00_static.txt

Then, you must build using the build command: west build -d <board name> -d build -- -DCONFIG_APP_MSC_STORAGE_SDCARD=y

as described here:

https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/samples/subsys/usb/mass/README.html#sd_card_example

Best regards,

Edvin

RE: Using SD card on nRF9161 DK

JOEBRE — Tue, 01 Jul 2025 07:10:28 GMT

Just to understand if there is something wrong with the sample or my SDK (v3.0.2 ) installation I generated a new mass storage project for nrf52840dk/nrf52840 (which is listed in the README file as a compatible board).

The sample doesn't build ...

C:/ncs/v3.0.2/nrf/include/flash_map_pm.h:47:22: error: 'PM_storage_partition_ID' undeclared (first use in this function)
47 | #define PM_ID(label) PM_##label##_ID

...

How shall I proceed to get this sample be configured and build correctly ?

Joel

RE: Using SD card on nRF9161 DK

JOEBRE — Mon, 30 Jun 2025 14:41:11 GMT

Hello... I formatted no the SD card with a FAT filesystem (to get at leas a starting point) ... I will switch to LittleFS later once things are working...

I'm using SDK v3.0.2 on visual studio code ith the v3.0.2 tool-chain. Looking at the README.rst description to build the usb mass storage it should be enough:

- create a new application using copy from sample (usb mass storage) sample

- add a build configuration with Board target set to nrf9161dc/nrf9161

- at this point (to build for SD card with SPI interface ) the README requires to invoke the build with the option -DCONFIG_APP_MSC_STORAGE_SDCARD=y (which I suppose is defining the symbol CONFIG_APP_MSC_STORAGE_SDCARD and sets it to the value y). Since I'm calling the build directly from VSCode... how should I set CONFIG_APP_MSC_STORAGE_SDCARD to y ? directly in prj.conf ? using Kconfig GUI ? ...

If I just build the application without any modification I get a compilation error stating:

C:/ncs/MyApp/mass_2/src/main.c:36:2: error: #error No supported disk driver enabled
36 | #error No supported disk driver enabled

Same thing if I add CONFIG_APP_MSC_STORAGE_SDCARD=y directly to prj.conf.

What do I need to set to successfully build this sample for SD card on SPI interface with FAT filesystem on nrf9161DK ?

RE: Using SD card on nRF9161 DK

Edvin — Mon, 30 Jun 2025 13:13:58 GMT

Can you try to format it using the mass storage sample? If you insert it and connect the DK with the nRF's USB port, does it show up at all in the listed drives attached to your computer? If not, do you have one of these USB->SD-card adapters that you can try to use?

Best regards,

Edvin

RE: Using SD card on nRF9161 DK

JOEBRE — Thu, 26 Jun 2025 15:14:33 GMT

Hello... before using the SD card.(mount it and write/read to it) I've to format it ... isn't it ?

The SD card gets now properly detected (disk_access_init):

*** Booting nRF Connect SDK v3.0.2-89ba1294ac9b ***
*** Using Zephyr OS v4.0.99-f791c49f492c ***
[00:00:00.252,471] <dbg> sd: sd_init_io: Host controller support 3.3V max
[00:00:00.252,471] <dbg> sd: sd_init_io: Resetting power to card
[00:00:00.256,195] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd0 arg 0x0
[00:00:00.256,988] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd8 arg 0x1aa
[00:00:00.257,751] <dbg> sd: sd_send_interface_condition: Found SDHC with CMD8 support
[00:00:00.257,781] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd59 arg 0x1
[00:00:00.258,544] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd58 arg 0x0
[00:00:00.259,429] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd55 arg 0x0
[00:00:00.260,223] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd41 arg 0x40000000
[00:00:00.271,087] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd55 arg 0x0
[00:00:00.271,881] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd41 arg 0x40000000
[00:00:00.272,644] <dbg> sd: sdmmc_send_ocr: SDMMC responded to ACMD41 after 1 attempts
[00:00:00.272,674] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd58 arg 0x40000000
[00:00:00.273,468] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd10 arg 0x0
[00:00:00.274,902] <dbg> sd: card_read_cid: Card MID: 0x3, OID: DS
[00:00:00.274,932] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd9 arg 0x0
[00:00:00.276,397] <dbg> sd: sdmmc_read_csd: Card block count 7744512, block size 512
[00:00:00.276,397] <inf> sd: Maximum SD clock is under 25MHz, using clock of 1000000Hz
[00:00:00.276,428] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd55 arg 0x0
[00:00:00.276,977] <dbg> sdhc_spi: sdhc_spi_send_cmd: cmd51 arg 0x0
[00:00:00.277,740] <dbg> sd: sdmmc_read_scr: SD reports specification version 8
[00:00:00.277,770] <inf> littlefs: LittleFS version 2.9, disk version 2.1

but I get an error calling:

#define MKFS_FS_TYPE FS_LITTLEFS
#define MKFS_DEV_ID "SDCard"
#define MKFS_FLAGS 0

fs_mkfs(MKFS_FS_TYPE, (uintptr_t)MKFS_DEV_ID, NULL, MKFS_FLAGS);

[00:00:00.277,770] <err> littlefs: Can't init littlefs backend, review configs and flags 0x00000000
[00:00:00.277,770] <err> fs: mkfs error (-134)

My .conf is:

CONFIG_DISK_ACCESS=y
CONFIG_DISK_DRIVERS=y
CONFIG_DISK_DRIVER_SDMMC=y

CONFIG_DEBUG=y
CONFIG_LOG=y
CONFIG_LOG_MODE_MINIMAL=n

CONFIG_FILE_SYSTEM=y
CONFIG_FILE_SYSTEM_LITTLEFS=y
CONFIG_FILE_SYSTEM_MKFS=y

CONFIG_FS_LITTLEFS_BLK_DEV=y
CONFIG_FS_LITTLEFS_FMP_DEV=n

Is there something missing ? how shall i call fs_mkfs in order to format the SD card ?

The USB mass storage code sample do not helps me a lot in the understanding on how to make the connection between LittleFS and the file system to the sd card driver ...

Is there anything missing the dts overlay (like partitions ... )? Sorry it may be a stupid question but I'm really new to Zephyr and the understanding is not immediate to me (if I understood it corectly mass storage sample supports only FAT as fs for SD card and not LittleFS on SD card).

Thx, Joel

RE: Using SD card on nRF9161 DK

Edvin — Thu, 26 Jun 2025 13:47:32 GMT

Hello Joel,

You can have a look at the USB Mass storage sample found in NCS\zephyr\samples\subsys\usb\mass.

Please check out the sample description found here, as this shows how to enable support for SD cards:

https://docs.nordicsemi.com/bundle/ncs-latest/page/zephyr/samples/subsys/usb/mass/README.html#usb-mass

Best regards,

Edvin

RE: Using SD card on nRF9161 DK

JOEBRE — Wed, 25 Jun 2025 13:49:19 GMT

After saving discovered that there is no way of using the SD card holder on the DK board, following the instructions found in this forum, I connected an external level shifter board ( 1.8-3 VDC) and a uDS card holder board to the nRF9161 DK board SPI has been connected to SPI3 on:

CLK -> P 0.13 (100 ohm termination resistors on the two drivers)

MISO -> P 0.12

MOSI -> P 0.11

CS -> P 0.10

I added the following stuff to the .overlay file:

&spi3 {
    cs-gpios = <&arduino_header 16 GPIO_ACTIVE_LOW>, /* D10 */
               <&gpio0          20 GPIO_ACTIVE_LOW>;

    sdhc0: sdhc@0 { // SPI SD card
        compatible = "zephyr,sdhc-spi-slot";
        reg = <0>; // First chip select in the spi3 definition
        status = "okay";
        mmc {
            compatible = "zephyr,sdmmc-disk";
            status = "okay";
            disk-name = "SDCard";
        };
        spi-max-frequency = <1000000>;
    };
};

Unfortunately I can't find anywhere instructions on how acceding this card using an LittleFS file system

How shall I proceed to make this SD card available to Zephyr trough LittleFS file system ?

Thanks, Joel

RE: Using SD card on nRF9161 DK

JOEBRE — Wed, 18 Jun 2025 06:04:45 GMT

Looking at the schematics of the nRF9161 DK with some more attention it becomes clear why the uSD card holder hasn't been soldered.

With the factory power supply configuration, J8 becomes useless (for an standard uSD card) ... there is no SD card on the market requiring only 1.8 VDC power supply ...

The easiest way to get uSD card support on nRF9161 is using an external level shifter module (1.8 -3.3 VDC) together with a uSD card holder module together with some flying wires ...

RE: Using SD card on nRF9161 DK

JOEBRE — Tue, 17 Jun 2025 12:14:20 GMT

Other issue... SD card in SPI mode requires power supply and signaling at 3.3 VDC. On the nRF9161 both power supply and signaling are at 1.8 VDC.

RE: Using SD card on nRF9161 DK

JOEBRE — Tue, 17 Jun 2025 11:21:53 GMT

Hello, I know it is a while now that this thread remained in an inactive state ... but now I'm back... I ordered the microSD card holder and it has been soldered on J8 on the bottom side of the DK... I was now taking a look into how to configure the nRF9161 to enable it to access the SD card via SPI... According to the DK schematic the chip select to P0.25, SCK to P0.21, MISO/DO P0.22 and these signals are OK. MOSI/DI instead is connected to the DBG_CMD signal which ends on pin 125 of the nRF9161 module. This pin, in the datasheet, is signed as "Do not connect/reserved for future use" ...

How can I use the SPI interface to control the SD card without using the MOSI ?

RE: Using SD card on nRF9161 DK

ketiljo — Fri, 07 Mar 2025 08:59:09 GMT

Ok, I see whay you mean. This is for internal debugging only. Here's how it's connected:

devzone.nordicsemi.com/.../pca10153_5F00_schematic_5F00_and_5F00_pcb.pdf

I guess you can mount the holder and access the SD card from the GPIOs it's connected to.

RE: Using SD card on nRF9161 DK

JOEBRE — Fri, 07 Mar 2025 06:51:34 GMT

Not really sure where do I find the version on the PCB... anyway i see a sticker reporting IMEI and PIN together with other numbers ... one of them seems to be a version number

PCA10153

1.0.0

2024.23

1050961666

RE: Using SD card on nRF9161 DK

ketiljo — Thu, 06 Mar 2025 21:55:08 GMT

What version of the DK do you have?