L2CAP layer question

RE: L2CAP layer question

alikob — Wed, 20 Sep 2017 14:21:09 GMT

Hey Petter, Thank you so much, that you shed some light to this issue, after your last comment, I found that this is L2CAP HID layer, its in this documents under HID section www.bluetooth.com/.../profiles-overview after reviewing 1.1.1 HID documents, I could decode 0xA1, which means A=data, and 1=input report, next byte 01 is for report ID for keyboard and 02 is report ID for Mouse, Now I need to know whats the next 2 bytes 0x00 0x20 for mouse report?

RE: L2CAP layer question

alikob — Wed, 20 Sep 2017 13:44:45 GMT

That's a great question, I am not sure, what BT that keyboard is generating, it might be just a classic BT, as you said, but I want to re-create that key in nRF51822 platform. Correct me if I am wrong, I think the main difference between the two version: classic and BLE starts with L2CAP data portion. May be if I find an example code for Nordic software to just send the raw L2CAP data portion, will do the job for me. But the data portion can also be mapped to some GATT protocol, with HID services, I think! I am too good at these stuff. Thanks for your help again.

RE: L2CAP layer question

Petter Myhre — Wed, 20 Sep 2017 13:33:59 GMT

That trace doesn't look like a Bluetooth low energy trace, are you sure it isn't Bluetooth Classic?

RE: L2CAP layer question

Petter Myhre — Wed, 20 Sep 2017 13:01:13 GMT

Can you please upload the complete trace so I can examine it here?

RE: L2CAP layer question

Petter Myhre — Wed, 20 Sep 2017 06:18:57 GMT

That doesn't make sense to me, but ok. Did you get this from a sniffer trace? Could you edit your question and upload your complete trace?

RE: L2CAP layer question

alikob — Wed, 20 Sep 2017 03:12:00 GMT

so what does 0xA1 and 0x01 means? I know the rest is part of HID keyboard code

RE: L2CAP layer question

Petter Myhre — Mon, 18 Sep 2017 14:27:24 GMT

Is this what you are doing? Credit based L2CAP connection? Where did you get the frame from?

RE: L2CAP layer question

Petter Myhre — Mon, 18 Sep 2017 14:26:21 GMT

According to Table 2.2 in Vol. 3, Part A, Section 2.1 in the Bluetooth Core specification 5.0 4D is:

0x0040-0x007F

Dynamically allocated Communicated using the

L2CAP LE credit based create connection mechanism(see Section 4.22)