Add EQ support for QuietComfort Headphones (prince)

README.md

@@ -26,7 +26,7 @@ connection to the headphones.
 | Device                      | NC Control                            | EQ     | Spatial        | Profiles              | Buttons                | Status             |
 | --------------------------- | ------------------------------------- | ------ | -------------- | --------------------- | ---------------------- | ------------------ |
 | **QC Ultra Headphones 2**   | CNC 0-10 slider                       | 3-band | room/head      | 7 custom slots        | Shortcut remap         | Verified           |
-| **QuietComfort Headphones** | CNC 0-10 + Wind Block via ModeConfig  | —      | field observed | 2 user slots observed | —                      | Verified (`prince`) |
+| **QuietComfort Headphones** | CNC 0-10 + Wind Block via ModeConfig  | 3-band | field observed | 2 user slots observed | —                      | Verified (`prince`) |
 | **QuietComfort 35 / 35 II** | ANR off/high/wind/low                 | —      | —              | —                     | Action remap (VPA/ANC) | Verified           |
 | **QuietComfort Earbuds**    | CNC 0-10 via direct SETGET            | 3-band | —              | 4 fixed modes         | Remap                  | Verified (`lando`) |
 | **QuietComfort 45**         | CNC 0-10 via ModeConfig               | 3-band | —              | 2 user slots          | Remap                  | Inferred (`duran`), untested on hardware |

cpp/src/devices.h

@@ -52,6 +52,7 @@ inline DeviceConfig qc_prince() {
     c.product_name = Addr{1, 2};
     c.voice_prompts = Addr{1, 3};
     c.cnc = Addr{1, 5};
+    c.eq = Addr{1, 7};
     c.pairing = Addr{4, 8};
     c.get_all_modes = Addr{31, 1};
     c.current_mode = Addr{31, 3};

cpp/tests/test_connection.cpp

@@ -100,6 +100,12 @@ TEST(qc35_no_eq) {
     ASSERT_FALSE(dev.has_feature("mode_config"));
 }
 
+TEST(prince_has_eq) {
+    auto t = std::make_unique<MockTransport>();
+    BmapConnection dev(std::move(t), qc_prince());
+    ASSERT_TRUE(dev.has_feature("eq"));
+}
+
 TEST(set_name_rejects_long_name) {
     bool threw = false;
     try { mock_qc_ultra2()->set_name(std::string(32, 'x')); }

docs/architecture.md

@@ -149,7 +149,7 @@ Each feature entry maps a name to its protocol address and codec functions:
 | RFCOMM channel | 2 | 8 | 8 |
 | Init packet | None | None | GET [0.1] required |
 | Noise control | CNC [1.5] / live [31.10] | CNC/wind via [31.6] ModeConfig | ANR [1.6] (off/high/wind/low) |
-| EQ | 3-band [1.7] | Not verified | Not supported |
+| EQ | 3-band [1.7] | 3-band [1.7] | Not supported |
 | Spatial audio | [31.6] ModeConfig | Field observed in [31.6] | Not supported |
 | Mode profiles | 7 editable slots (4-10) | 2 editable slots observed (2-3) | None |
 | Sidetone | [1.11] | Not verified | [1.11] |

docs/quietcomfort-headphones-prince.md

@@ -155,6 +155,21 @@ wind:   0 -> 1 -> 0
 
 These writes applied immediately when the edited slot was the current mode.
 
+## EQ
+
+`prince` exposes the same 3-band equalizer register as `qc45` and
+`qc_ultra2`:
+
+```
+[1.7] RangeControl/EQ GET/SETGET
+```
+
+A GET returns 4-byte groups `[min, max, current, band_id]` with signed
+`-10..+10` values. SETGET writes one band per packet as `[value, band_id]`
+(`0` = bass, `1` = mid, `2` = treble). Verified on firmware
+1.0.6-80+f5f219b: a read returned Bass +6 / Mid +5 / Treble +6, and a write
+round-tripped through a subsequent read.
+
 ## Unsupported or Not Yet Verified
 
 The tested firmware does not support QC Ultra 2's direct live settings register:
@@ -179,5 +194,5 @@ No unauthenticated true ANC-off toggle was found:
 | `[1.5]` SettingsCnc SETGET with disable flag | rejected/auth gated |
 
 The verified local controls are mode switching, editable-mode raw CNC level,
-and Wind Block. EQ, buttons, multipoint, power, and true ANC off remain
-unverified for `prince`.
+Wind Block, and 3-band EQ. Buttons, multipoint, power, and true ANC off
+remain unverified for `prince`.

python/pybmap/devices/qc_prince.py

@@ -48,6 +48,13 @@
         "addr": (1, 5),
         "parser": parsers.parse_cnc,
     },
+    # 3-band EQ. Same Settings-block register as qc45/qc_ultra2/qc_earbuds;
+    # verified working on prince firmware 1.0.6-80+f5f219b (range -10..+10).
+    "eq": {
+        "addr": (1, 7),
+        "parser": parsers.parse_eq,
+        "builder": parsers.build_eq_band,
+    },
     "pairing": {
         "addr": (4, 8),
     },

python/tests/test_qc_prince.py

@@ -0,0 +1,40 @@
+"""Tests for QuietComfort Headphones (prince) device configuration."""
+
+from pybmap.devices import qc_prince, parsers, DEVICES
+
+
+class TestQCPrinceConfig:
+    def test_qc_prince_registered(self):
+        assert "qc_prince" in DEVICES
+
+    def test_has_device_info(self):
+        assert qc_prince.DEVICE_INFO["product_id"] == 0x4075
+        assert qc_prince.DEVICE_INFO["codename"] == "prince"
+
+    def test_has_core_features(self):
+        for feat in ["battery", "firmware", "product_name", "voice_prompts",
+                      "cnc", "eq", "pairing"]:
+            assert feat in qc_prince.FEATURES, "Missing feature: %s" % feat
+
+    def test_rfcomm_channel_8(self):
+        assert qc_prince.RFCOMM_CHANNEL == 8
+
+    def test_eq_register_and_parsers(self):
+        eq = qc_prince.FEATURES["eq"]
+        assert eq["addr"] == (1, 7)
+        assert eq["parser"] is parsers.parse_eq
+        assert eq["builder"] is parsers.build_eq_band
+
+    def test_eq_builder_encodes_signed_value(self):
+        assert parsers.build_eq_band(-2, 0) == bytes([0xFE, 0x00])
+        assert parsers.build_eq_band(3, 2) == bytes([0x03, 0x02])
+
+    def test_no_audio_settings(self):
+        assert "audio_settings" not in qc_prince.FEATURES
+
+    def test_preset_modes(self):
+        assert qc_prince.PRESET_MODES["quiet"]["idx"] == 0
+        assert qc_prince.PRESET_MODES["aware"]["idx"] == 1
+
+    def test_editable_slots(self):
+        assert qc_prince.EDITABLE_SLOTS == [2, 3]

rust/src/devices.rs

@@ -68,7 +68,7 @@ pub fn qc_prince() -> DeviceConfig {
         product_name: Some(Addr(1, 2)),
         voice_prompts: Some(Addr(1, 3)),
         cnc: Some(Addr(1, 5)),
-        eq: None,
+        eq: Some(Addr(1, 7)),
         buttons: None,
         multipoint: None,
         sidetone: None,
@@ -310,6 +310,7 @@ mod tests {
         assert_eq!(dev.info.codename, "prince");
         assert_eq!(dev.rfcomm_channel, 8);
         assert!(dev.mode_config.is_some());
+        assert!(dev.eq.is_some());
         assert!(dev.audio_settings.is_none());
         assert!(!dev.supports_anc_toggle);
         assert_eq!(dev.editable_slots, &[2, 3]);