NRF52840 as USB peripheral and USB host.

RE: NRF52840 as USB peripheral and USB host.

Vidar Berg — Fri, 13 Jan 2023 08:41:55 GMT

Hi Snehal,

Yes, that is why I do not understand why you are enabling a RAM disk.

Regards,

Vidar

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Fri, 13 Jan 2023 07:26:09 GMT

Hi Vidar,

My goal is to create a file inside the flash memory chip. And when USB is plugged into the device it should be seen as a drive on laptop/desktop and I should be able to access the file which was created in the flash chip.

Regards,

Snehal

RE: NRF52840 as USB peripheral and USB host.

Vidar Berg — Fri, 13 Jan 2023 07:21:50 GMT

Hi Snehal,

What is the RAM disk going to be used for?

Regards,

Vidar

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Fri, 13 Jan 2023 05:30:38 GMT

Hi Vidar,

I changed the values according to the ble_app_hrs_freertos example.

FLASH_PH_START=0x0
FLASH_PH_SIZE=0x100000
RAM_PH_START=0x20000000
RAM_PH_SIZE=0x40000
FLASH_START=0x27000
FLASH_SIZE=0xd9000
RAM_START=0x20005978
RAM_SIZE=0x3a688

FLASH RX 0x0 0x100000;RAM1 RWX 0x20000000 0x40000

But still it is giving me the same errors. I guess the issue is in usb file attached below.

The RAM_BLOCK_DEVICE_SIZE is defined as (380 * 512) which is taking a lot of space I assume.

When I change it to (100*100) I am able to compile the code.

But the code says Windows fails to format volumes smaller than 190KB.

Can you suggest something?

. devzone.nordicsemi.com/.../usb_5F00_msc.c

Thanks & Regards,

Snehal.

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Fri, 13 Jan 2023 04:12:41 GMT

Okay I will try and get back.

RE: NRF52840 as USB peripheral and USB host.

Vidar Berg — Thu, 12 Jan 2023 13:57:28 GMT

The section placement macros you posted earlier appear to be for the nRF52833, not the nRF52840 which has 256K of RAM and 1MB of flash. Please use the 'pca10056' configuration for the ble_app_hrs_freertos example as a reference for what values to use.

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Thu, 12 Jan 2023 09:36:18 GMT

I have SPI,I2C,BLE,DFU all in my project along with new USB MSC drivers. My code uses FreeRTOS.

I would have uploaded the code but having currently having issues uploading it. Can you suggest how to increase RAM?

Thanks & Regards,

Snehal.

RE: NRF52840 as USB peripheral and USB host.

Vidar Berg — Thu, 12 Jan 2023 08:46:19 GMT

The linker error shows that you do not have any RAM left, so we need to find out what is taking up this much RAM in your application. Can you upload it here?

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Thu, 12 Jan 2023 07:36:29 GMT

OK.. Currently I am trying to test the code. I have included all drivers in my source code. I am getting following error after adding all drivers:-

My Flash placement is like this . The project includes BLE drivers as well

How can I solve this??

Thanks & Regards,

Snehal.

RE: NRF52840 as USB peripheral and USB host.

Vidar Berg — Thu, 12 Jan 2023 07:24:35 GMT

It basically says that the nRF will not have access to the filesystem as long as the board is connected to a PC. This would have been clear if you had tested the example.

Regards,

Vidar

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Thu, 12 Jan 2023 05:19:17 GMT

Hi Vidar,

I found one more thing on nordic dev infocenter page.

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v17.1.0%2Fusbd_msc_example.html

Please check the highlighted lines. It is saying that if USB is connected, access to the file system from a user application is not possible because MSC is not designed to allow access to the file system from multiple sources. But my application on desktop would like to view the files and view the content inside it.

I am stuck here if this will be useful??

Regards,

Snehal

RE: NRF52840 as USB peripheral and USB host.

Vidar Berg — Tue, 10 Jan 2023 15:06:21 GMT

Hi Snehal,

Windows does not have native support for littlefs like it does for FAT, so I guess you do not what want to use littflefs for this.

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Tue, 10 Jan 2023 14:35:45 GMT

Hi Vidar,

One thing I noticed is the USB MSC code already has 2 files for FAT FS diskio_blkdev.c and ff.c.

I guess this will help implementing File system on the flash chip. Do i still need to include the littlefs library??

https://github.com/littlefs-project/littlefs

Regards,

Snehal.

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Thu, 05 Jan 2023 12:39:46 GMT

Ok.. I have found one library for Case 1. It is for STM32 but guess can use that.

https://github.com/jakakordez/max3421e-stm32/tree/master/Src

But here I saw some USB related files too. So doubtful whether those should be included or our USB MSC will do the task.

RE: NRF52840 as USB peripheral and USB host.

Vidar Berg — Thu, 05 Jan 2023 12:37:34 GMT

Yes. But we do not have a USB stack that works with the MAX3421.

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Thu, 05 Jan 2023 12:37:14 GMT

So if Case 1 also requires USB stack, will USB MSC work for both the cases?

RE: NRF52840 as USB peripheral and USB host.

Vidar Berg — Thu, 05 Jan 2023 12:26:38 GMT

Hi Snehal,

Sorry, I missed the fact that you were planning to expose an additional USB interface with the MAX3421. I am not familiar with this chip, but from the datasheet it looks like it only handles low-level protocol operations. Thus, requiring a USB stack with host support to be integrated on your nRF52840. I suggest you contact the chip vendor and ask if they have any reference code available for your use case.

2. You can use the USB MSC Example for this part.

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Thu, 05 Jan 2023 12:02:01 GMT

Hi Vidar,

There are 2 cases in my project:-

1) ID accessory(pen drive) ----> NRF52840.

In case 1 NRF52840 should act as a USB host and detect the ID accessory as well as do some data transfer. As nrf sdk does not support USB host operation, we are going to use MAX3421.

2)NRF52840 ----> Desktop

In case 2 NRF52840 will be connected to the desktop and it should be detected as a drive on the desktop. Here Nor flash is also attached to the NRF52840 where sensor data will be saved. I will be mounting file system on this NOR flash. So when nrf52840 is connected to the desktop, the user should be able to see the files from the flash.

What USB drivers do I need to use in Case 1 & Case 2 respectively. This is my confusion. Please help.

Thanks,

Snehal.

RE: NRF52840 as USB peripheral and USB host.

Vidar Berg — Wed, 04 Jan 2023 07:54:13 GMT

Hi Snehal,

I suggest you try the examples to see how they work. If you want your USB to show up as a mass storage device (like a USB flash drive) you should use the USB MSC Example which enables the USB Mass Storage Class.

RE: NRF52840 as USB peripheral and USB host.

sne_333 — Wed, 04 Jan 2023 04:57:19 GMT

Hi Vidar,

Will I be able to debug and flash the code into device after implementing USB CDC ACM Example?

What is the difference between USB class storage module ,USB CDC ACM & usbd_ble_uart? Which one will be best suited for my application?

I am also having an external NOR flash attached to nrf52840 via SPI. To mount the file system on the NOR flash I am going to use littlefs library. The main goal is that whenever the device is plugged into the laptop, we should be able to see the device as a drive and we should be able to access the files from the external flash just like we access any pendrive when it is attached to the laptop.

Will USB MSC code work for above application?

Thanks,

Snehal

RE: NRF52840 as USB peripheral and USB host.

Vidar Berg — Tue, 03 Jan 2023 14:55:38 GMT

Hi,

For USB, I would suggest starting with something simple like the USB CDC ACM Example. Your board should then show up as a virtual COM port on your PC when the USB is connected. Next step can be to integrate the SPI sensor and relay the data to the COM port.

Best regards,

Vidar