feat: Allow limiting max. volume

Signed-off-by: Matthias Blankertz <matthias@blankertz.org>

software/frontend/index.html

@@ -354,7 +354,8 @@
             'root.BUTTON_MAP.PLAY_PAUSE': 'Play/Pause',
             'root.TAG_TIMEOUT_SECS': 'Tag removal timeout (seconds)',
             'root.TAGMODE': 'Tag mode',
-            'root.LED_COUNT': 'Length of WS2182 (Neopixel) LED chain'
+            'root.LED_COUNT': 'Length of WS2182 (Neopixel) LED chain',
+            'root.VOLUME_MAX': 'Maximum volume (0-255)'
         };
         const config_input_override = {
             'root.TAGMODE': {
@@ -393,6 +394,9 @@
             },
             'root.WLAN.PASSPHRASE': {
                 'input-type': 'text'
+            },
+            'root.VOLUME_MAX': {
+                'input-type': 'number'
             }
         };
     

software/src/app.py

@@ -9,8 +9,8 @@ from utils import TimerManager
 Dependencies = namedtuple('Dependencies', ('mp3player', 'nfcreader', 'buttons', 'playlistdb', 'hwconfig', 'leds',
                                            'config'))
 
-# Should be ~ 6dB steps
-VOLUME_CURVE = [1, 2, 4, 8, 16, 32, 63, 126, 251]
+# Should be ~ 3dB steps
+VOLUME_CURVE = [1, 2, 3, 4, 6, 8, 11, 16, 23, 32, 45, 64, 91, 128, 181, 255]
 
 
 class PlayerApp:
@@ -52,6 +52,7 @@ class PlayerApp:
         self.hwconfig = deps.hwconfig(self)
         self.leds = deps.leds(self)
         self.tag_mode = self.config.get_tagmode()
+        self.volume_max = self.config.get_volume_max()
         self.playing_tag = None
         self.playlist = None
         self.buttons = deps.buttons(self) if deps.buttons is not None else None
@@ -91,8 +92,10 @@ class PlayerApp:
     def onButtonPressed(self, what):
         assert self.buttons is not None
         if what == self.buttons.VOLUP:
-            self.volume_pos = min(self.volume_pos + 1, len(VOLUME_CURVE) - 1)
-            self.player.set_volume(VOLUME_CURVE[self.volume_pos])
+            new_volume = min(self.volume_pos + 1, len(VOLUME_CURVE) - 1)
+            if VOLUME_CURVE[new_volume] <= self.volume_max:
+                self.volume_pos = new_volume
+                self.player.set_volume(VOLUME_CURVE[self.volume_pos])
         elif what == self.buttons.VOLDOWN:
             self.volume_pos = max(self.volume_pos - 1, 0)
             self.player.set_volume(VOLUME_CURVE[self.volume_pos])

software/src/utils/config.py

@@ -26,7 +26,8 @@ class Configuration:
         'WIFI': {
             'SSID': '',
             'PASSPHRASE': '',
-        }
+        },
+        'VOLUME_MAX': 255
     }
 
     def __init__(self, config_path='/config.json'):
@@ -97,6 +98,9 @@ class Configuration:
     def get_wifi_passphrase(self) -> str:
         return self._get('WIFI')['PASSPHRASE']
 
+    def get_volume_max(self) -> int:
+        return self._get('VOLUME_MAX')
+
     # For the web API
     def get_config(self) -> Mapping[str, Any]:
         return self.config

software/tests/test_playerapp.py

@@ -139,6 +139,9 @@ class FakeConfig:
     def get_tagmode(self):
         return 'tagremains'
 
+    def get_volume_max(self):
+        return 255
+
 
 def fake_open(filename, mode):
     return FakeFile(filename, mode)