G522's 0x020D V2 uses a 5-byte band stride
[freq_hi, freq_lo, gain_i8, q_hi, q_lo] and a 13-byte getEQInfos
(gain bounds, gain_steps, format, xy, preset counts). Frequency and
Q are opaque u16 round-trip values — the u16->Hz and u16->Q mappings
need a LGHUB pcap to pin down (documented in
~/ghub/HEADSET_ADVANCED_PARA_EQ_WIRE_PROTOCOL.md).
get_advanced_eq_info now returns a dict with a `version` discriminator
and the union of V0/V1 and V2 fields; step_db is derived from the
gain_min/gain_max/gain_steps triple on V2 (0.05 dB/LSB on G522).
get_advanced_eq_params version-switches: V2 uses parse_v2_bands which
probes header length {5, 2, 0} until the tail is a clean multiple of
5, strips trailing all-zero terminator entries. V0/V1 falls through
to the legacy 3-byte stride so older devices still work.
HeadsetAdvancedEQ.build() no longer requires band_count from
getEQInfos (V2 doesn't advertise it); derives from getCustomEQ length
per the wire-protocol doc's recommendation. V2 band labels use
"Band N" since u16->Hz isn't confirmed. Read-only still — writes
stay gated until pcap confirms the encodings.
Centurion feature discovery now logs each parent + sub-device feature at
INFO with name/index/version/flags. `check_feature` logs INFO when it
skips a setting for min_version or the INTERNAL flag. HeadsetAdvancedEQ
and HeadsetOnboardEQ `build()` paths log at every failure branch. The
three AdvancedParaEQ helpers log raw response bytes.
On the G522, `HEADSET_ADVANCED_PARA_EQ` (0x020D) is present in the
feature set but no settings panel appears and current logging gives us
no way to tell which step silently returns None.
The G522 exposes AdvancedParaEQ (0x020D), a different EQ feature than
the PRO X 2's OnboardEQ (0x0636). Key differences:
- 3-byte-per-band wire format ([freq_hi, freq_lo, gain]) vs 0x0636's
4-byte-per-band ([freq_hi, freq_lo, gain, Q])
- Device handles biquad coefficient computation — no host-side DSP math
- Has explicit direction (playback/capture), multiple preset slots with
getActiveEQ/setActiveEQ for switching, preset friendly names
Adds new advanced_para_eq.py module with getInfos, getActiveEQ, and
getCustomEQ helpers (function 0, 3, 1 respectively). Re-exported from
hidpp20.py following the onboard_eq.py pattern.
HeadsetAdvancedEQ setting displays the currently-active playback EQ
using the same RangeFieldSetting + PackedRangeValidator UI pattern as
HeadsetOnboardEQ, so the graphic EQ widget looks the same.
**Writes are intentionally disabled for now** — prepare_write returns
None and write() logs "read-only mode" without sending anything. This
lets us verify the wire format matches the protocol doc against real
hardware before risking a write that could misconfigure the DSP. Once
read output is confirmed sensible, we'll wire up setCustomEQ (function
2) to enable writes.
Ken Sanislo