Slow BLE data transfer with Android

RE: Slow BLE data transfer with Android

Edvin — Mon, 03 Feb 2025 08:01:10 GMT

Hello,

Sorry for the late reply!

Thank you for the update. It is difficult to say the exact reason, without the sniffer trace from the original Android and iOS connections, but I guess the issue is connection parameters related. There are some more connection parameters that you can tweak as well, and you do not necessarily get the connection parameters that you request from the peripheral application (since it is the central device that decides the actual connection parameters). Please have a look at the Nordic Developer Academy Bluetooth Low Energy Fundamentals course. Particularly Lesson 3 talks about connection parameters. What you can adjust, and how to do it. It also provides callbacks that tells you what connection parameters you actually end up with. You can use this to compare the connection parameters with the Android and iOS connection.

https://academy.nordicsemi.com/courses/bluetooth-low-energy-fundamentals/lessons/lesson-3-bluetooth-le-connections/topic/blefund-lesson-3-exercise-2/

Best regards,

Edvin

RE: Slow BLE data transfer with Android

Rantanplan — Thu, 30 Jan 2025 10:15:07 GMT

Hello,

we added the

bt_le_conn_param *conn_param = BT_LE_CONN_PARAM(INTERVAL_MIN, INTERVAL_MAX, 0, 50);

err = bt_conn_le_param_update(conn, conn_param);

in the BLE connected callback.

That improved the situation for Android as well.

Kind regards,

Christian

RE: Slow BLE data transfer with Android

Rantanplan — Sat, 25 Jan 2025 14:30:15 GMT

I now sniffed the BLE packets and with Android I shows a lot of L2CAP Messages with "Retransmit", which is not the case in iOS.

devzone.nordicsemi.com/.../android_5F00_sniff.pdf