USB MSC code, windows not able to access drive.

[Ash-tink]

I am using the USB MSC code in my project. The project works fine and I am able to see the file system mounted and file being created in the logs. When I plug in the device into my laptop, I can see the device as a drive. However, when I click to access the drive, it asks me to format the drive and I am not able to view the contents of the drive. What might be causing this issue?

[Simonr]

Hi

What SDK and SDK version have you used for development? Are you able to recreate this on a Development Kit? If so we can narrow it down to SW instead of HW at least.

Best regards,

Simon

[Ash-tink]

I am using sdk 17.0.0. The main issue is I am not able to see any errors while mounting the File system. Is it possible that the file system mounting does not show any errors but still has some configuration errors?? 

[Simonr]

Hi

There could be unreported errors, depending on whether you log the callback of each function or not, but it's important here that nRF5 SDK v17.0.0 is not recommended for development. There were some issues with this release, and it's strongly recommended to switch to v17.0.2 or v17.1.0 (stated in the release notes here).

Best regards,

Simon

[Ash-tink]

Sorry my SDK is 17.0.2 only. I misread it . what should be the configuration of the flash chip inside this function if my flash is 4Mbit?

The below config is taken from example code. 

static const nrf_serial_flash_params_t m_sflash_params[] = {
 { /*MXIC MX25R6435F*/
 .read_id = { 0xEF,0x60,0x17 },
 .capabilities = 0x00,
 .size = 8 * 1024 * 1024,
 .erase_size = 2 * 1024,
 .program_size = 256,
 }
};

And what should be the Block size,MSC_WORKBUFFER_SIZE & format size for 4Mbit flash?

[Simonr]

Hi Snehal

The .size set by default is for a 64Mbit flash (8 MByte). 1024*1024 = 1 MB, so you can multipy that with how many MB the used flash device is. Since 4Mbit is the same as 0.5 MB, the .size should be set to 0.5 * 1024 *1024, or 512 * 1024 simplified. MSC_WORKBUFFER_SIZE is the buffer that gets actual payload from the USB. This buffer is subdivided into 2 smaller buffers and they should have the size of a single block.

Best regards,

Simon

[Ash-tink]

Thanks for your reply.  So that means the .size will be set to  524288. Now for setting MSC_WORKBUFFER_SIZE, how can we determine the size of a single block?

If we set the config as follows:-

NRF_BLOCK_DEV_SPI_DEFINE(
m_block_dev_spi,
NRF_BLOCK_DEV_SPI_CONFIG(
512,
NRF_BLOCK_DEV_SPI_FLAG_CACHE_WRITEBACK,
NRF_DRV_SPI_DEFAULT_CONFIG
),
NFR_BLOCK_DEV_INFO_CONFIG("Nordic", "SPI", "1.00")
);

then the block size will be 512?? 

So MSC_WORKBUFFER_SIZE should be set to 1024 right? 

But even after doing these settings I am still not able to access drive through laptop.

[Ash-tink]

I have also added some logs in the usb msc drivers to check for any errors. I have attached the log file here. Can you please help me debugging it?

RTT-DEBUG1.log