Max throghtput nrf52 survey

RE: Max throghtput nrf52 survey

Bjørn Kvaale — Mon, 15 Jul 2019 12:12:46 GMT

The problem with iOS in general is that Apple limits the timeslot that you can use for BLE. This is to ensure that both BLE & WiFi get enough timeslot to work reliably. Therefore, you won't see such great throughput values on iPhones. Android phones, especially the Samsung Galaxy S8 & S8 Plus, do not have these limitations. Therefore, you will see better values there.

Have you tested with a Samsung Galaxy S8? Or do you only want to use iOS devices? If I remember correctly, we have noticed values around 600 kbps for some iOS devices.

RE: Max throghtput nrf52 survey

Lucasm27 — Mon, 15 Jul 2019 10:52:10 GMT

Unfortunately, under all the tests we carry out with the 52840 DK development board and some phones, we are forced to try to find another solution or hardware. Although in the theory the BLE 5.0 achieves a certain speed of transmission, in a more practical environment and diverse devices it does not fulfill our expectations.
For the one that interests us we achieve with an Iphone 8 ( manufactured with BLE 5.0), using the throughput demo, configured with the parameters that Apple specifies for that device and the nrfConnect app a maximum continuous of 330 Kbits / s.

If someone thinks it is improvable, for me it would be an option to continue with the tests.

Regards

RE: Max throghtput nrf52 survey

Lucasm27 — Thu, 11 Jul 2019 18:03:18 GMT

Thanks Bjorn. I'll study your info. Then I can write about the test.

RE: Max throghtput nrf52 survey

Bjørn Kvaale — Thu, 11 Jul 2019 12:19:51 GMT

Hopefully one of these links will be helpful: link 1, link 2, link 3.

RE: Max throghtput nrf52 survey

Lucasm27 — Thu, 11 Jul 2019 07:13:38 GMT

First of all I appreciate the interest. Second point out the problem if the thread doesn't make sense. My intention is to make a survey to people who have experience in testing a nrf52840 (peripheral device) with a smartphone (central device). Within those hardware requirements consult how to achieve the greatest possible transfer.
1- Within the points to compare the operating system (Android or iOS) can be in play.
2- Parameterization of the "peripheral" equipment firmware.
3- Configuration of the "central" equipment software.

RE: Max throghtput nrf52 survey

awneil — Wed, 10 Jul 2019 19:22:52 GMT

I don't think that Android or iOS will ever give you "maximum possible".

You could build yourself a custom Central - eg, an nRF52840 Dongle - so then you have full control ...

RE: Max throghtput nrf52 survey

Lucasm27 — Wed, 10 Jul 2019 17:48:41 GMT

This is a test , but our requirement will be achieve "minimum acceptable " as "maximum possible". You should think that our device must be able the transmiting the contents of a flash memory ( 128 Mbit). The time is relevant for doing this operation.

Like many of topics on internet or differents blogs the overinformation is not our friend.

RE: Max throghtput nrf52 survey

awneil — Wed, 10 Jul 2019 17:14:42 GMT

The Peripheral does get notified of what Connection Parameters have been granted.

So you can define what is your "minimum acceptable" and, if you don't get that, notify the user somehow.

Both Android & iOS do give some recommendations - you'd have to search their documentation for details...

RE: Max throghtput nrf52 survey

Lucasm27 — Wed, 10 Jul 2019 16:55:44 GMT

Ok ... this could be one piece of this puzzle.

Assuming that we would like to achieve a high-speed cross-platform transfer (android-ios)

What guidelines should We consider?

RE: Max throghtput nrf52 survey

awneil — Wed, 10 Jul 2019 15:32:45 GMT

Note that it is the phone which decides the actual Connection Interval used - not the Peripheral.

The Peripheral makes a request to the phone, but the phone makes the actual decision - it is not obliged to accept the request!

And, in fact, phones will usually not accept (very) small connection intervals.

And the connection interval that they do grant is not (necessarily) fixed: it can - and does - vary from connection to connection on the same phone.

This comes up frequently ...

RE: Max throghtput nrf52 survey

Lucasm27 — Wed, 10 Jul 2019 15:01:25 GMT

Bjorn this is a nice throughput. You can help me with the test. We deal with the following devices One plus 2, iphone 6 and iphone 8.

In our first approach to test it, We use the SDK example att_mtu througtput . We changed the paramethers related at the transfer speed on the file sdk_config.h. The result was under the 300 kbps.

paramethers

NRF_BLE_SCAN_MIN_CONNECTION_INTERVAL

NRF_BLE_SCAN_SCAN_PHY

NRF_SDH_BLE_GATT_MAX_MTU_SIZE

NRF_SDH_BLE_GAP_DATA_LENGTH

You gime some advice or provide me your configuration or project for read.

I don't mensioned We use a nrf52840 DK on segger studio without ext antenna.

P.D. In another post I read some changes related at the RAM...?

RE: Max throghtput nrf52 survey

Bjørn Kvaale — Wed, 10 Jul 2019 08:11:45 GMT

We have measured around 1200 kbps with the Samsung S8 phone.