BLE NUS Data Length 243 Bytes instead of 244 Bytes

[kdot88]

Hello,

Utilizing NRF52840 with the NUS profile + 2Mbps PHY + DLE enabled.

NRF_SDH_BLE_GAP_DATA_LENGTH = 251

NRF_SDH_BLE_GATT_MAX_MTU_SIZE = 247

Testing with iOS, data transmit  / receive is working fine, however I can only receive 243 bytes whereas I am expecting 244 bytes per the BLE standard. Assuming 3-byte ATT header and 4-byte L2CAP header. What is the reason for the extra byte missing?

[Sigurd]

Hi,

I'm not sure how you are testing this, if I were to guess, it could be that last character is the new line character, '\n', at the end, and that it therefore seems like it's missing one character.

But we likely would need some nrf_logs, and sniffer logs to confirm: https://www.nordicsemi.com/Products/Development-tools/nrf-sniffer-for-bluetooth-le

[kdot88]

Hi Sigurd,

This turned out to be an issue on our configuration on the iOS side.  Thanks for the reply but we can close this ticket.

[L.Marie]

Hi, 
I observe the same issue.
Could you tell me how you managed it?