Auracast OPEN failure.

[andrew_ts]

Module / firmware

AudioAgent IDC777 V3.2.72
Build: 0400427b
Bluetooth address 245DFC03C101

Manual reference: AAGENT-IDC777-V32xx.

Broadcast source: standalone Auracast broadcaster, unencrypted, broadcast_id 0x123456, broadcast_name 24_7_Abba.

What works — OPENANY connects and streams:

OPENANY
> OPENANY
< PENDING
< OPENANY_SCAN_OK
< OPEN_OK 1A BRX1 DFAD02270C16
< LC3_BROADCAST_NUMBER_BIS 2
< LC3_BROADCAST_STREAM_CONNECT

What fails — SCAN reports the broadcaster, then OPEN fed with the exact reported values fails:

SCAN 2 OFF 2
> SCAN 2 OFF 2
< PENDING
< SCAN 2 DFAD02270C16 1 0x123456 0x0 24_7_Abba -54 OFF OFF OFF OFF
< SCAN_OK

OPEN DFAD02270C16 BRX1 2 0 123456
> OPEN DFAD02270C16 BRX1 2 0 123456
< PENDING
< OPEN_ERROR DFAD02270C16 BRX1 0

Per the manual, the SCAN response for filter=2 is SCAN , and the corresponding command is OPEN BRX1 . The OPEN call above uses those values verbatim: addr_type=2, adv_sid=0 (from the 0x0 in the SCAN), bcast_id=123456. It fails after ~4 s with reason 0 (“general failure / device was there but could not connect” per the error-codes table), even though OPENANY syncs to the same train moments later.

What we need

1. The correct OPEN ... BRX1 parameter mapping for AA32xx V3.2.72 — especially whether semantics have changed since AAGENT-IDC777-V32xx.
2. Confirmation of whether OPEN ... BRX1 is still supported, or whether OPENANY (+ OPENANY_CONFIG filtering) is the intended path going forward.

[andrew_ts]

Of course the solution presented itself five minutes after raising this ticket. The nRF5340 EVK I am using as a test auracast server is unable to generate a truly public address as it has no assigned MAC and is therefore advertising a private but non-rotating BT address in the auracast advertisement. I had not spotted this and was using the incorrect address type in the OPEN command. When I corrected this to “1” the OPEN command works. 

I think we can close this one and call it a win.

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