DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

RE: DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

Samiulhaq — Wed, 28 Sep 2022 10:54:40 GMT

Thank you for the reply,

I have created the thread but I can't get helped properly. I have applied all the suggestions but can't reduce my data transfer time.

Regards,

Sami

RE: DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

Jørgen Holmefjord — Wed, 28 Sep 2022 10:52:11 GMT

I see you have already created a new ticket here: Sending a complete file at once from SD card to Mobile App using NRF52840.

Please continue the discussion in that thread.

RE: DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

Samiulhaq — Wed, 28 Sep 2022 09:32:23 GMT

Thank you for the replay,

My question is exactly the same( reading file from SD card and sending to Mobile App) the only difference is file size which is 240MB in my case and nothing else. I have read almost all related threads but no one help me.

Till now I am able to read 220kb of data from the file in the SD card (the actual size of the file is 240MB) and send it to the mobile app(using the above example you have provided, with some modifications) and it is taking about 4 seconds to send 220kb of data. I want to reduce the time taken for the data to send to the Mobile app, I have applied all the suggestions in multiple threads but can't reduce the time to send the data to the mobile app.

Any help will be highly appreciated.

Kind Regards,

Sami

RE: DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

Jørgen Holmefjord — Wed, 28 Sep 2022 09:06:10 GMT

Please post your questions in a new ticket, as this is not related to the topic of this thread. Your questions relates to general BLE throughput and BLE services, which are already discussed in multiple threads. Please search other threads before posting your questions.

RE: DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

Samiulhaq — Wed, 28 Sep 2022 04:55:37 GMT

Hi Jorgen, thank you for the reply.

Yes, I understand that. You can't send more than a specific amount of bytes in one go using ble_uart. I have two questions:

1) Is there another possible way to send a file to the mobile app other than the ble_Uart?

2) What is the minimum time through which I can send a 234MB file to the mobile App?

I have read this blog in which they claim "The throughput measured may vary depending on the environment, but the maximum throughput should be around 1365 Kbps for BLE 5 High Speed, 775 Kbps for BLE 4.2, 128 Kbps for BLE 4.1 and 21.3 Kbps for BLE 5 Long Range. Be aware that there may be some inaccuracies in the measurements". How can I achieve this much throughput?

RE: DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

Jørgen Holmefjord — Tue, 27 Sep 2022 15:31:24 GMT

Hi,

It is not possible to send 240 MB over BLE in one go, you will have to divide the file into smaller chunks that can fit inside the BLE packets.

Best regards,
Jørgen

RE: DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

Samiulhaq — Fri, 23 Sep 2022 11:26:13 GMT

Hey Jorgen, thanks for the example. I have a large file of 240MB on an SD card and I want to transfer this file to the mobile app at once not byte by byte just like you have done in the above example. The byte by byte transfer will take a lot of time as the file size is large and also controlling it on the app side will be difficult. So, I want to transfer my file to the App at once. Can you please recommend to me the fastest possible to do it,

Thanks & best regards,

Sami

RE: DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

Turbo J — Sat, 14 Dec 2019 13:46:13 GMT

Does the STM32 support USB host mode (or OTG)? You need this in order to be able to connect to an NRF chip, as these can only be in USB device role.

If the STM32 cannot be USB Host, you are probably better off connecting these chips via SPI.

RE: DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

jagannathan GOPALAKRISHNAN — Sat, 14 Dec 2019 10:11:29 GMT

Thanks Mr. Jorgen. It worked. I need one more help. I want to connect the USB to a device other than Computer. We are using the STM32bit controller. can u suggest.

RE: DATA FILE TRANSFER FROM SD CARD TO MOBILE USING USB PROTOCOL. HOW TO DO IT IN NRF52840

Jørgen Holmefjord — Wed, 11 Dec 2019 15:24:46 GMT

Hi,

I created an example with ble_app_uart that read a specified file on boot and when a central is connected and notifications for NUS are enabled, the file is transferred to the central.

This example is created using SDK v16.0.0.

devzone.nordicsemi.com/.../ble_5F00_app_5F00_uart_5F00_fatfs_5F00_send_5F00_sdk_5F00_16.0.0.zip

Best regards,
Jørgen