feat(free): allow pick start without fretboard using expert-stop key

Normal-mode pick with no fret held applies the last expert stop transpose, starts on I, and arms even-beat stop if idle.

Co-authored-by: Cursor <cursoragent@cursor.com>

Global/Global.c

@@ -105,7 +105,7 @@ int16_t MIC_VOL_MAP[11]= {-9000,-7000,-5000,-3000,-1000,1000,3000,5000,7000,9000
 
 uint8_t TOUCH_AREA_NUM = (sizeof(Touch_Areas)/sizeof(Touch_AreaTypeDef));
 
-const uint8_t Version[3] = {0,2,23}; /* major.minor.patch — 0.2.23: 万能拨片先前奏再循环段落1 */
+const uint8_t Version[3] = {0,2,24}; /* major.minor.patch — 0.2.24: 普通无指板也可拨片起奏(用专业停键调性)+偶拍停 */
 uint8_t Led = 8;
 bool PressFlag = 0;
 
@@ -647,6 +647,33 @@ void Accomp_ApplyDefaultIChord(void)
   PressFlag = 0;
 }
 
+/* 专业模式按停止键时记住当前调性，供普通模式无指板拨片起奏使用 */
+static uint8_t s_expert_stop_transpose = 0;
+static uint8_t s_expert_stop_transpose_valid = 0;
+
+static void Expert_RememberStopTranspose(void)
+{
+  uint8_t tab = (uint8_t)mGuiData[GUI_TAB_INDEX].Current;
+  uint8_t last = (uint8_t)mGuiData[GUI_TAB_LAST_INDEX].Current;
+
+  if (tab == 1 || (tab == 3 && last == 1))
+  {
+    s_expert_stop_transpose = (uint8_t)mGuiData[GUI_TRANSPOSE].Current;
+    s_expert_stop_transpose_valid = 1;
+  }
+}
+
+/* 普通无指板拨片：套用上次专业停键调性（无记录则保持当前移调） */
+static void FreeMode_ApplyExpertStopTranspose(void)
+{
+  if (!s_expert_stop_transpose_valid)
+    return;
+  if ((uint8_t)mGuiData[GUI_TRANSPOSE].Current == s_expert_stop_transpose)
+    return;
+  mGuiData[GUI_TRANSPOSE].Current = s_expert_stop_transpose;
+  UITask_Sendmsg(MSG_ID_BLE_UI_REFRESH, GUI_TRANSPOSE, 0, 0);
+}
+
 void Accomp_UpdatePlayingChord(void)
 {
   uint8_t midi_note_buff[4] = {0,};
@@ -684,6 +711,7 @@ extern uint8_t m_ABSystem[];
 #define AB_STAGE_POST       0x0Cu
 
 static void FreeMode_CancelEvenBeatStop(void);
+static void FreeMode_ArmEvenBeatStop(void);
 
 static void Accomp_FireSectionNotes(void)
 {
@@ -1092,6 +1120,7 @@ static void Band_AllNotesOff(void)
  * 库 Stop 之后第一个 Start 必被吞，立即拨片无声。 */
 void Stop_AutoBand_Soft(void)
 {
+  Expert_RememberStopTranspose();
   FreeMode_CancelEvenBeatStop();
   Band_CancelStartFollowup();
   Band_TickGate = 0;
@@ -1107,6 +1136,7 @@ void Stop_AutoBand_Soft(void)
 
 void Stop_AutoBand()
 {  
+  Expert_RememberStopTranspose();
   FreeMode_CancelEvenBeatStop();
   /* 先清播放态，再 Stop/AllNoteOff，避免处理期间其它路径误判在播 */
   Band_CancelStartFollowup();
@@ -1546,9 +1576,20 @@ void Pick_Handle()
     return;
   }
 
-  /* 左手未触发和弦板（或落在拍速/停止键）时：拨片默认发当前调一级大和弦伴奏；
+  /* 左手未触发和弦板（或落在拍速/停止键）时：拨片默认发当前调一级大和弦伴奏。
-   * 普通模式除外——必须左手按住指板再拨，不做一级兜底（说明书需求） */
+   * 普通模式无指板也可起奏：调性用上次专业停键时的移调，起奏后无操作则偶拍停。 */
-  if (mGuiData[GUI_TAB_INDEX].Current != 2 &&
+  {
+  uint8_t free_pick_no_fret =
+      (mGuiData[GUI_TAB_INDEX].Current == 2 &&
+       (PressFlag == 0 || chord_id == 0 || chord_id > 21)) ? 1u : 0u;
+
+  if (free_pick_no_fret)
+  {
+    FreeMode_ApplyExpertStopTranspose();
+    Accomp_ApplyDefaultIChord();
+    chord_id = KEY_ID_1629;
+  }
+  else if (mGuiData[GUI_TAB_INDEX].Current != 2 &&
            (chord_id == 0 || chord_id == 22 || chord_id == 23))
   {
     Accomp_ApplyDefaultIChord();
@@ -1592,14 +1633,9 @@ void Pick_Handle()
       break;
 
       case 2:
-          /* 普通：左手按住指板 + 拨片起奏；松手由 TM1629 停。
+          /* 普通：可无指板拨片起奏（一级+专业停键调性）；有指板则用当前和弦。
+           * 无指板起奏后若无其它操作，偶拍末停；按住指板则循环至松手再偶拍停。
            * 节奏用 piece；本地曲目用 StartWithNote */
-          if (PressFlag == 0 || chord_id == 0 || chord_id > 21)
-          {
-              LOG_I("pick", "normal skip press=%u chord=%u (need fretboard)",
-                    (unsigned)PressFlag, (unsigned)chord_id);
-              break;
-          }
           {
           uint8_t session_was_on = StartFlag ? 1u : 0u;
           StartFlag = 1;
@@ -1617,18 +1653,24 @@ void Pick_Handle()
               AutoBandTop1_SetRunVar(mGuiData[GUI_PLAY_SECTION].Current);
               midi = 0x3C + mGuiData[GUI_TRANSPOSE].Current;
               Band_StartLocalRetry(midi, midi_note_buff, note_cnt);
-              LOG_I("pick", "local/normal root=%u name=%s", midi,
+              LOG_I("pick", "local/normal root=%u name=%s noFret=%u", midi,
-                    AutoBandTop1_GetPresetName() ? AutoBandTop1_GetPresetName() : "?");
+                    AutoBandTop1_GetPresetName() ? AutoBandTop1_GetPresetName() : "?",
+                    (unsigned)free_pick_no_fret);
           }
           else
           {
               AutoBandTop1_SetPiecePlayMode(1, 0, 1920);
               Band_StartPieceRetry(midi_note_buff, note_cnt);
               AutoBandTop1_SetLoopMode(0, 1);
-              LOG_I("pick", "normal/rhythm piece name=%s notes=%u chord=%u",
+              LOG_I("pick", "normal/rhythm piece name=%s notes=%u chord=%u noFret=%u xp=%u",
                     AutoBandTop1_GetPresetName() ? AutoBandTop1_GetPresetName() : "?",
-                    (unsigned)note_cnt, (unsigned)chord_id);
+                    (unsigned)note_cnt, (unsigned)chord_id,
+                    (unsigned)free_pick_no_fret,
+                    (unsigned)mGuiData[GUI_TRANSPOSE].Current);
           }
+          /* 无指板：起奏后即武装偶拍停；有指板则等松手再 Arm */
+          if (free_pick_no_fret)
+            FreeMode_ArmEvenBeatStop();
           }
       break;
 
@@ -1652,6 +1694,7 @@ void Pick_Handle()
                (unsigned)PressFlag, (unsigned)note_cnt, (unsigned)chord_id);
       break;
     }
+  }
 }