How to enable Data Length Extension (DLE)?

[HarryWindsor]

One of the features highlights of NimBLE is the "support for 251 byte packet size". How do I enable "Data Length Extension" (DLE) to send packages of size 251 instead of 27 bytes of data?

I have set my MTU to 256 bytes and just send dummy data. This generates multiple messages of size 32 bytes (each with 27 bytes of data).

Below is a screenshot from wireshark:

[Massimiliano-solutiontech]

+1

[rahult-github]

Hi, ble_hs_hci_util_set_data_len is the API available here that can be used for this.

Thanks, Rahul

[Massimiliano-solutiontech]

Thanks for the response but the function signature that I have is slightly different:

int ble_hs_hci_util_set_data_len(uint16_t conn_handle, uint16_t tx_octets, uint16_t tx_time)

how about the tx_time parameter?

Thanks, Massimiliano

[rahult-github]

My bad, copy pasted incorrect line. The signature you mentioned is correct:

https://github.com/espressif/esp-nimble/blob/nimble-1.3.0-idf/nimble/host/src/ble_hs_hci_util.c#L125

[Massimiliano-solutiontech]

@rahult-github sorry for the late response but I had corona, I tried as you suggested ble_hs_hci_util_set_data_len and the return code is 0 but when I try to transfer a file is still sent in small packets

[HarryWindsor]

It has be enabled from the client