NRF5340 Max throughput

RE: NRF5340 Max throughput

Vidar Berg — Mon, 11 Apr 2022 11:58:55 GMT

Glad to hear that it worked.

I have not been able to reach 1.3 Mb/s with the pc-ble-driver, and I think it's a combination of overhead of having the serialized softdevice communication and latency introduced by the USB transport. Scheduling of USB events on the PC may be delayed by other OS tasks.

RE: NRF5340 Max throughput

Branislav — Mon, 11 Apr 2022 11:51:11 GMT

Thank you, that was the reason why the throughput was so slow with 400ms connection interval, this is the result I get after changing the event length:

There are some weird packet issues for the first 20 seconds of the stream tho.

I only want to circle back to my previous question, would it be possible to achieve 1.3 Mb/s throughput with the nrf52840 dongle or is this the limit of the hardware/default firmware?

RE: NRF5340 Max throughput

Vidar Berg — Mon, 11 Apr 2022 11:22:15 GMT

Sorry, I did not notice the other screenshot. I only saw the one where you got the low throughput @ 400 ms. A likely explanation for this is that the connection event length is too short. The connection event length can be configured when you enable the BLE stack on the dongle.

I increased the event length to 400 ms at line 141 in this pc-ble-driver-py script:

devzone.nordicsemi.com/.../4010.nus_5F00_central.py

RE: NRF5340 Max throughput

Branislav — Mon, 11 Apr 2022 10:24:23 GMT

The results I get from your app are in the same range as the screenshot I have posted, the troughput is 1110 - 1133 kbps.

And no, blatann doesn't support long mtu packets, my question is is there something that can be done on the side of the dongle to get the rest of the throughput that has been measured when using two dev boards.

And do you maybe know why do those meausrements work well with 400 ms connection interval while in this scenario only 7.5 ms inteval gives the best throughput?

RE: NRF5340 Max throughput

Vidar Berg — Mon, 11 Apr 2022 10:19:24 GMT

Hi,

You mean you get the same result if you use my FW or if you use the nRF connect app? I am not sure if the blatann script is configured to support long MTU and radio packets which will have a significant impact on the throughput.

Thanks,

RE: NRF5340 Max throughput

Branislav — Mon, 11 Apr 2022 10:12:31 GMT

Hi Vidar,

Yes, those are the same results I'm getting on my end.
Is there a way to get a better throughput with central, without making a custom firmware for the dongle, or is this that can be done with the current official firwmare?

RE: NRF5340 Max throughput

Vidar Berg — Mon, 11 Apr 2022 09:28:14 GMT

Hello,

The throughput may also be limited by the Central (PC in this case). I made a test based on the peripheral_uart sample to test the same here and I was able to get around 1000 kbps (also limited by central). This test app starts sending notifications with dummy data as soon as soon as the client enables the notifications. It then it prints the measured throughput out on UART.

Could you try it and see if you get a comparable results? Here is the project I used:

devzone.nordicsemi.com/.../peripheral_5F00_uart_5F00_throughput_5F00_test.zip

My setup:

- Bluetooth low enegery app v3.0.1 in nRF connect for desktop

- nRF52840 Dongle

- nRF5340DK

Result:

Best regards,

Vidar