feat:adjust gain in speaker volume. add led and auto-disconnect toggle in mute.

src/audio.cpp

@@ -6,6 +6,7 @@
 #include "bt.h"
 #include "resample.h"
 #include "tusb.h"
+#include "usb.h"
 #include <algorithm>
 
 #define INPUT_CHANNELS    4
@@ -13,7 +14,7 @@
 #define SAMPLE_SIZE       64
 #define REPORT_SIZE       142
 #define REPORT_ID         0x32
-#define VOLUME_GAIN       2
+// #define VOLUME_GAIN       2
 #define BUFFER_LENGTH     55
 
 static WDL_Resampler resampler;
@@ -49,8 +50,8 @@ void audio_loop() {
 
     // 4. 转换为int8并缓冲，满64字节即组包发送
     for (int i = 0; i < out_frames; i++) {
-        int val_l = (int) (out_buf[i * 2] * 127.0f * VOLUME_GAIN);
-        int val_r = (int) (out_buf[i * 2 + 1] * 127.0f * VOLUME_GAIN);
+        int val_l = (int) (out_buf[i * 2] * 127.0f * (volume[0] ?: 1));
+        int val_r = (int) (out_buf[i * 2 + 1] * 127.0f * (volume[0] ?: 1));
         haptic_buf[haptic_buf_pos++] = (int8_t) std::clamp(val_l, -128, 127); // 似乎clamp有点多余？还是以防万一吧
         haptic_buf[haptic_buf_pos++] = (int8_t) std::clamp(val_r, -128, 127);