Ble 5 send large data

RE: Ble 5 send large data

Simonr — Tue, 11 Jul 2023 07:01:51 GMT

As I suggested initially, I'd use the object transfer service to transmit multiple kB of data, or alternatively our throughput sample to transmit a lot of data at the same time. You can use the Image transfer demo we made here for reference that continuously transmits data from an nRF52 to an Android device.

If the throughput doesn't matter, you can use the Nordic UART service as well, but the buffer size will need to be increased to fit 5kB I believe, but this is not what the Nordic UART service is designed for.

Best regards,

Simon

RE: Ble 5 send large data

mte1 — Mon, 10 Jul 2023 08:03:33 GMT

Thank you, i understand. I have last question, if i choose to send 20bytes in one advertise, which function should i use to send for example 5kB of data. Time doesn't matter here, i just want to share this data between two nrf52 development kits.

will uint32_t ble_nus_data_send(ble_nus_t * p_nus, uint8_t * p_data, uint16_t * p_length, uint16_t conn_handle) be good at it? And how is this "queued" to send kilobytes? It's function from ble_app_uart example.

RE: Ble 5 send large data

Simonr — Mon, 10 Jul 2023 07:57:26 GMT

It's not possible to transmit 247 bytes "per package" with extended advertising, as the "extended" part of the advertisement will occur on secondary channels compared to the initial advertising event. But you can inded transmit 247 bytes over advertising if that's what you want. Please keep in mind though that the transmission will not be encrypted, so any BLE 5.0 scanners will be able to pick up on these transmission. So you'll get better both encryption and throughput by doing this within a connection.

See this blog post on BLE 5.0 advertising for more information, alternatively check out the DevAcademy, that has a course on BLE fundamentals as a whole.

Best regards,

Simon

RE: Ble 5 send large data

mte1 — Fri, 07 Jul 2023 07:40:59 GMT

Thanks, i'll check the blog post and go through the examples.

Is it possible to change ble_app_beacon example to send 247 bytes per package?

RE: Ble 5 send large data

Simonr — Thu, 06 Jul 2023 10:41:05 GMT

Please check out this excellent blog post over at NovelBits that explain and test the maximum throughput over BLE 5 using the nRF52840: https://novelbits.io/bluetooth-5-speed-maximum-throughput/

Something like the object transfer service is best suited for transmitting larger blobs of data over .

Best regards,

Simon