Speed up caracteristic reading

[Olfox]

Hi,

I'm using 52833 and S113.

My system works well, i have all my caracteristic and i'm able to read it out with nRfConnect mobile app.

But it is terribly slow .

I mean, to read out  my eeprom carac , 256 bytes, it last 4 seconds !

And my data , 132 bytes that i should read each 100ms, takes around 2 seconds.

I checked the #define setting on top of the main, but i see no parametres that i could adjust to speed up this.

I hope there something to do otherwise, my application will never work as it should.

Thanks for your help !

[Hung Bui]

Hi Florian, 

Have you tried to reduce the connection interval ? Usually it's the MIN_CONN_INTERVAL and MAX_CONN_INTERVAL you set in main.c 

Try putting it down to 20ms for example. 

How did you send the data ? Have you made sure you filled in all the buffer when sending data ? 

I would suggest to capture a sniffer trace so we can get to understand what's going on over the air. 

[Olfox]

Hi Hung,

Thanks for your advise, i reduce from 100 -200 to 10-20 and it is much more fast !  How to kow how many byte per packet are transfered and is it possible de change it ? it could may be again increase the data rate ?

[Hung Bui]

Good to hear. You can monitor the NRF_BLE_GATT_EVT_ATT_MTU_UPDATED event to get the ATT_MTU updated. 

You can also use a sniffer to capture what happens over the air. It can give you a lot of information. 

[Olfox]

yes i have seen your first proposal. but it seems we need to have a second dev board or dongle to it ? it can not be only windows pc ?

[Hung Bui]

Yes, you need a 2nd dev board for it , the dongle wouldn't work. And it can run on Linux as far as I know (wireshark application)