Transmitting large data (NRF5340 Audio DK)

[pal_722]

Hi,

I am currently working on creating a Custom Profile, and have used Peripheral Sample code. I tweaked the code and was able to send 512 bytes of data on 8 different characteristics each, but when i tried to send 1024 bytes and 2048 bytes, I loose data. 

I want to send 1024 bytes or more (basically 2's power data) of data for my Application.
Can someone help me with this?

Thank you 
Regards
Pallavi

[Susheel Nuguru]

Can you please give us more details on how exactly you are trying to send 1024 and 2048 bytes of data, and what do you mean by losing data? the data never appears in the application? BLE is an acknowledge based protocol, so it means that the data is received by the controller and mostly the host, it is most of the time application corner cases, where data is lost. If you give more specific details and probably some code snippets demonstrating what you are trying to do, then we can attempt to assist you.

[pal_722]

Hi Susheel Nuguru , Thanks for the reply.

Susheel Nuguru said:

the data never appears in the application?

Yes. I do not receive the data in the app. 

i am trying to send VND_MAX_LEN number of 1's to each characteristic.

I had used the existing Peripheral sample code to customize my application. 
Please let me know if you need any further details.

Thank you!
Regards
Pallavi

[Susheel Nuguru]

Normally you need to increase the BLE TX buffers if you want to send data in bigger chunks, there are quite a lot of parameters that come to play but you can start with checking with some TX buffer size in your config. With DLE enabled, you should have some thing like below for TX buffers

CONFIG_BT_L2CAP_TX_MTU=247
CONFIG_BT_BUF_ACL_TX_SIZE=251
CONFIG_BT_BUF_ACL_TX_COUNT=10
CONFIG_BT_BUF_ACL_RX_COUNT=10
CONFIG_BT_BUF_ACL_RX_SIZE=251

If you have a sniffer that you can sniff to see more details that is happening in the air transactions, then we can get some more info on the transactions size and timings.

[pal_722]

Hi Susheel Nuguru 

I used these buffers, and found there is no change in the reception of data. If I try sending any data above 512 bytes, the max I receive is 600 bytes.

Not sure what am I doing wrong. Is streaming useful? Can I stream the data, so that I can receive as many bytes as I want?

Thanks and Regards