nRF5340PDK Throughput example, very low throughput.

[Florin Mazilu]

Hi! 

I was trying the throughput example using two nRF5340PDK boards and I observed the throughput is very low, i.e. 1kpbs. I tried programming the cpuappns, but it didn't work correctly, it displayed other stuff on the terminal emulator:

 

And when I tried programming on the cpuapp, the throughput was 1kbps:

I tried modifying the .conf files, by adding the lines:

CONFIG_BT_CTLR_TX_BUFFER_SIZE=251
CONFIG_BT_CTLR_DATA_LENGTH_MAX=251
CONFIG_BT_RX_BUF_LEN=255

But the throughput stayed the same. 

 Why would the Bluetooth be so slow? What should I do to maximize the throughput?

Thank you,

Florin Mazilu.

[ovrebekk]

Hi Florin

When running Bluetooth examples on the nRF5340 application core, the network core will be automatically flashed with the hci_rpmsg example, and it is actually for this example you need to change the Bluetooth configuration. 

In other words you need to change the prj.conf file in the \zephyr\samples\bluetooth\hci_rpmsg folder, and then rebuild your nRF53 project. 

Can you give this a go and see if it fixes the throughput issue?

Best regards
Torbjørn

[Florin Mazilu]

Hi Torbjørn

I added those lines to prj.conf from the hci_rpmsg folder, but now I get an error when I build the solution:

If I remove those three lines the solution builds without errors.

Thank you,

Florin.

[ovrebekk]

Hi Florin

In v1.4.0 of NCS I have not been able to reproduce this issue, no. I just tested it again and both using the older PDK's and the newer DK's I am getting good throughput. 

I did notice that the newer 1.4.99-dev1 tag of NCS did not show give similar results, possibly there is an issue here. 

Can you confirm which version of NCS you are using?

Best regards
Torbjørn

[Florin Mazilu]

Hi

So at first I was using v1.4.1, then I tried v1.4.99-dev1 and v.1.4.2, but none of the worked. So now I went back to v1.4.1

Thank you,

Florin.

[ovrebekk]

Hi Florin

Do you mean you have the same issue in all versions, or is it working fine in v1.4.1?

Best regards
Torbjørn

[Florin Mazilu]

Hi Torbjørn

Sorry for the ambiguousness, I have the same issue in all versions.

Thank you,

Florin 

[ovrebekk]

Hi Florin

That is odd. I downloaded a fresh install of v1.4.2 and tried again, and even when using only the older nRF5340PDK's I don't see any issues with the throughput. 

Can you please try my hex files and see if they give you the expected throughput on your kits?

hex_files.zip

If you run the bat file it should do a full recover of the board and flash the application and network core with the right files. 

I recommend only turning on one kit at the time, otherwise you will have to enter the board number over and over. 

The code is built for the nRF5340PDK, not the nRF5340DK, so it assumes you have the older boards. 

Best regards
Torbjørn

[Florin Mazilu]

Hi Torbjørn

So I tried your hex files and it worked very well, I got a throughput of around 1.2Mbps. I tried programming the boards using the SEGGER IDE (v1.4.1 of SDK) and it still works, the throughput is still 1.1-1.2Mbps.

Thank you for your help!

Florin.

[ovrebekk]

Hi Florin

That is excellent news, glad to hear you got it working

I will consider this case resolved then. 

Best regards
Torbjørn