File transfer from SD Card to WiFi using nRF5340 and nRF7002 - recommended signal wiring

RE: File transfer from SD Card to WiFi using nRF5340 and nRF7002 - recommended signal wiring

Håkon Alseth — Mon, 21 Aug 2023 13:53:18 GMT

Hi,

My apologies for the long wait.

Unfortunately, we do not have a sample that does exactly what you require at this time.

We have an open PR for the download sample, where we are adding nRF7002 support. However, this is currently work-in-progress:

https://github.com/nrfconnect/sdk-nrf/pull/11547

I would recommend disabling CONFIG_LOG and also disable CONFIG_DOWNLOAD_CLIENT_RANGE_REQUESTS to get better performance at this time. Reason for this is that the internal download thread is running on the same priority as the log thread, which will cause a performance hit.

In addition, there is currently a progress-print that you can comment out in main.c:

https://github.com/nrfconnect/sdk-nrf/blob/3a85b431d94137081e76ee48dce873ef8412211c/samples/net/download/src/main.c#L187

Again, this PR is not currently optimized for speed and is a work-in-progress. The maintainer of the PR is aware of this.

Kind regards,

Håkon

RE: File transfer from SD Card to WiFi using nRF5340 and nRF7002 - recommended signal wiring

Bruno Saraiva — Tue, 15 Aug 2023 18:17:25 GMT

Do you or any colleague has written a speed test for transferring SD card files via WiFi using 5340 and 7002? I wonder what the numbers would show and where the bottleneck would be...
Unfortunately I really don't have the time to learn to write such test, but being something relatively common, it would be useful for many other customers.
We are proceeding with the design anyway, but aligning the expectations up front will be useful.
Thanks!

RE: File transfer from SD Card to WiFi using nRF5340 and nRF7002 - recommended signal wiring

Håkon Alseth — Mon, 14 Aug 2023 14:35:44 GMT

Hi,

You'll need to involve the CPU in the process, but the payload also needs to be encapsulated through the TCP/IP stack as well.

Kind regards,

Håkon

RE: File transfer from SD Card to WiFi using nRF5340 and nRF7002 - recommended signal wiring

Bruno Saraiva — Mon, 14 Aug 2023 13:56:59 GMT

Ok then...
"SDCard -> SPI -> DMA -> CPU RAM Buffer ->
CPU RAM Buffer -> DMA -> QSPI -> nRF7002"
🙂

RE: File transfer from SD Card to WiFi using nRF5340 and nRF7002 - recommended signal wiring

Håkon Alseth — Mon, 14 Aug 2023 13:28:28 GMT

Hi,

[quote user="Bruno Saraiva"]"SDCard -> SPI -> CPU DMA -> QSPI -> nRF7002"[/quote]

We do not have generic DMA channels, so this is not possible, unfortunately.

Kind regards,

Håkon

RE: File transfer from SD Card to WiFi using nRF5340 and nRF7002 - recommended signal wiring

Bruno Saraiva — Mon, 14 Aug 2023 13:05:43 GMT

Thank you for the comments and the links. 🙂
I had no idea about this SD license requirement!

As for the original question, we will be adopting the only possible option:
"SDCard -> SPI -> CPU DMA -> QSPI -> nRF7002"

RE: File transfer from SD Card to WiFi using nRF5340 and nRF7002 - recommended signal wiring

Håkon Alseth — Mon, 14 Aug 2023 12:46:15 GMT

The QSPI peripheral is targeted for NOR based flash operations on both nRF52840 and nRF5340, and will not work with an SD card.

SD cards also require an additional license: RE: nRF5340, QSPI and micro SD

Kind regards,

Håkon

RE: File transfer from SD Card to WiFi using nRF5340 and nRF7002 - recommended signal wiring

Bruno Saraiva — Sat, 12 Aug 2023 12:35:41 GMT

Thanks for the quick feedback!

Really no QSPI for SD allowed?? Do you have off hand any document reference to that?

The current version of our product has SD Card, and I know that the traces were routed between the nRF5340 and the uSD as QSPI. Also, I can confirm that the product works (writing/reading lots of files to the uSD).
But I was not involved in the software, so maybe my colleagues configured those pins as regular SPI instead and I never knew it...

Or a separate point: do you know if the data transfer can be really "raw bytes" from the SD to the nRF7002, and the TCP packages are dealt inside that component, or is it handled by the code that runs inside the nRF5340?

RE: File transfer from SD Card to WiFi using nRF5340 and nRF7002 - recommended signal wiring

Turbo J — Fri, 11 Aug 2023 18:19:16 GMT

You can't use the QSPI peripherial with an SD card, so only method 2 is possible.