How to increase the MTU size in NRF52833?

[lara]

I have tried the below in proj.conf.iam using NRF52833 DK in VS CODE(NRF SDK Connect extension.Iam trying to receive data through gatt protocol,but it is not receiving more than 20 bytes.

toolchain version 2.8

also my build log showing ...

Memory region         Used Size  Region Size  %age Used
           FLASH:      203344 B       248 KB     80.07%
             RAM:       29188 B        32 KB     89.07%
        IDT_LIST:          0 GB        32 KB      0.00%

according to datasheet..512 KB Flash + 128 KB RAM for NRF52833DK.but the build log showing only 32kB of RAM,248kB of Flash.why?

CONFIG_BT_USER_DATA_LEN_UPDATE=y

CONFIG_BT_L2CAP_TX_MTU=247

CONFIG_BT_BUF_ACL_TX_SIZE=251

CONFIG_BT_BUF_ACL_RX_SIZE=251

[Simonr]

What is the device you're connecting to here. I don't think this is directly related to the RAM and Flash memory allocated to your device, but rather the connection being the restricting factor of the MTU size that's being set. Are you connecting to a phone, another nRF52 series DK or a computer here? It will always be the central device that has the final say in an MTU exchange, and if it doesn't agree or support with the suggested MTU size from the peripheral, it can always lower this to whatever it supports. So please share some details on the device you're connecting to.

Best regards,

Simon

[lara]

iam using NRF52833DK,enabled GATT. my central device is mobile phone.in nrf connect app,iam connecting with nrf52833 and giving the input.it receives the input only less than 62 bytes

[Simonr]

What phone is this exactly, an iOS device or Android device, and which model? You should be able to see some logging in the nRF Connect app for mobile as well (by swiping right on Android for example). Do you see any information about the MTU exchange on the phone side of things?

Best regards,

Simon

[lara]

iam using android phone,realme 5 pro.giving input through nrf connect app