pbio/drv/sound: add default volume config option

Add a default volume configuration option for each platform that
supports sound. The EV3 speaker can be quite loud, so we don't want
it to default to 100%.

Author: dlech

lib/pbio/platform/ev3/pbdrvconfig.h

@@ -72,6 +72,7 @@
 
 #define PBDRV_CONFIG_SOUND                          (1)
 #define PBDRV_CONFIG_SOUND_EV3                      (1)
+#define PBDRV_CONFIG_SOUND_DEFAULT_VOLUME           75
 
 #define PBDRV_CONFIG_UART                           (1)
 #define PBDRV_CONFIG_UART_DEBUG_FIRST_PORT          (1)

lib/pbio/platform/nxt/pbdrvconfig.h

@@ -42,6 +42,7 @@
 #define PBDRV_CONFIG_RESET_NXT                      (1)
 
 #define PBDRV_CONFIG_SOUND                          (1)
+#define PBDRV_CONFIG_SOUND_DEFAULT_VOLUME           100
 #define PBDRV_CONFIG_SOUND_SAMPLED                  (1)
 #define PBDRV_CONFIG_SOUND_BEEP_SAMPLED             (1)
 #define PBDRV_CONFIG_SOUND_NXT                      (1)

lib/pbio/platform/prime_hub/pbdrvconfig.h

@@ -104,6 +104,7 @@
 #define PBDRV_CONFIG_RESISTOR_LADDER_NUM_DEV        (2)
 
 #define PBDRV_CONFIG_SOUND                          (1)
+#define PBDRV_CONFIG_SOUND_DEFAULT_VOLUME           100
 #define PBDRV_CONFIG_SOUND_SAMPLED                  (1)
 #define PBDRV_CONFIG_SOUND_BEEP_SAMPLED             (1)
 #define PBDRV_CONFIG_SOUND_STM32_HAL_DAC            (1)

pybricks/common/pb_type_speaker.c

@@ -79,7 +79,7 @@ static mp_obj_t pb_type_Speaker_make_new(const mp_obj_type_t *type, size_t n_arg
 
     // REVISIT: If a user creates two Speaker instances, this will reset the volume settings for both.
     // If done only once per singleton, however, altered volume settings would be persisted between program runs.
-    self->volume = 100;
+    self->volume = PBDRV_CONFIG_SOUND_DEFAULT_VOLUME;
     self->sample_attenuator = INT16_MAX;
 
     return MP_OBJ_FROM_PTR(self);