DFU - SDK 14.1.0 - Support for higher MTUs added.

RE: DFU - SDK 14.1.0 - Support for higher MTUs added.

Hung Bui — Wed, 25 Oct 2017 13:20:41 GMT

Can't you just create one ? If you look in main.c of the throughput example you can find m_gatt is init in gatt_init().

To be able to verify that data length extension and large ATT MTU is working, I would suggest you to use a sniffer to capture the communication. Or at least monitor the events and check if the request actually works.

RE: DFU - SDK 14.1.0 - Support for higher MTUs added.

schef — Wed, 25 Oct 2017 08:53:37 GMT

I have some problems with gatt. The function calls (void) nrf_ble_gatt_data_length_set(&m_gatt, BLE_CONN_HANDLE_INVALID, data_length); but there is no &m_gatt in nrf_ble_dfu.c.

RE: DFU - SDK 14.1.0 - Support for higher MTUs added.

Hung Bui — Tue, 24 Oct 2017 13:18:08 GMT

No, they are not the same. Have a look here.

RE: DFU - SDK 14.1.0 - Support for higher MTUs added.

schef — Tue, 24 Oct 2017 12:13:14 GMT

Isnt Data length extension same as using NRF_SDH_BLE_GATT_MAX_MTU_SIZE 247?

RE: DFU - SDK 14.1.0 - Support for higher MTUs added.

Hung Bui — Tue, 24 Oct 2017 09:31:13 GMT

Hi Schef,

I don't think longer MTU size is supported on the DFU firmware on SDK v14.1

But you can try to increase it, simply increase NRF_SDH_BLE_GATT_MAX_MTU_SIZE to 247 as in our \ble_central_and_peripheral\experimental\ble_app_att_mtu_throughput example.

You can follow the example to see how you can increase the throughput on DFU.

Note that increasing MTU wouldn't improve through put significantly. Because it's only save some header bytes. The packet on air under L2CAP stays the same.

What can improve through put more significantly is Data length extension. But I don't think it can be handled from the app. The phone OS controls that. Also, note that not all the phones support all BLE 4.2 or v5.0 features.