Add buzzer examples and modernize Buzzer init

Add XRPExamples/buzzer_examples.py demonstrating basic note playback, custom songs, background playback with movement, and driving+beeping examples.

Refactor XRPLib/buzzer.py: remove unused urandom import and the fixed BUZZER_PIN constant; change constructor to accept buzzer_pin (int|str) and prefer a BOARD_BUZZER entry on machine.Pin.board when no pin is provided, otherwise raise a clear exception. Initialize PWM duty to 0 on creation.

Update XRPLib/defaults.py to detect a board buzzer using hasattr(Pin.board, "BOARD_BUZZER") before creating the buzzer instance. These changes make buzzer configuration more flexible and explicit for boards with a predefined buzzer pin.

Author: SaintSampo

XRPExamples/buzzer_examples.py

@@ -0,0 +1,85 @@
+from lib.XRPLib.buzzer import Buzzer
+from XRPLib.defaults import *
+import time
+
+"""
+    By the end of this file students will learn how to use the Buzzer class
+    to play individual notes, custom songs, and how to make the robot 
+    play music while it is moving.
+"""
+
+# Get the singleton instance of the buzzer
+buzzer = Buzzer.get_default_buzzer()
+
+def simple_scale():
+    """Plays a basic C major scale."""
+    print("Playing a simple scale...")
+    notes = ["C4", "D4", "E4", "F4", "G4", "A4", "B4", "C5"]
+    for note in notes:
+        buzzer.play_note(note, "quarter")
+
+def custom_song_example():
+    """Demonstrates how to create and play a custom list of notes."""
+    print("Playing a custom melody...")
+    # A song is a list of (note, duration) tuples
+    # Durations can be "whole", "half", "quarter", "eighth", "sixteenth"
+    my_song = [
+        ("E4", "eighth"), ("G4", "eighth"), ("E5", "quarter"),
+        ("rest", "eighth"),
+        ("C4", "quarter"), ("G3", "half")
+    ]
+    
+    # Set tempo to 140 Beats Per Minute
+    buzzer.set_tempo(140)
+    buzzer.play_song(my_song)
+
+def siren():
+    """Simple two-tone siren effect using individual notes."""
+    print("Siren started!")
+    for _ in range(3):
+        buzzer.play_note("A4", "quarter")
+        buzzer.play_note("E4", "quarter")
+
+def musical_robot():
+    """
+    Playing music while driving.
+    We use blocking=False so the code continues to the next line 
+    while the music plays in the background.
+    """
+    print("Dancing with music!")
+    
+    # Start 'Move It' in the background
+    buzzer.play_move_it(blocking=False)
+    
+    # While the song is playing, the robot can perform actions
+    for i in range(4):
+        drivetrain.set_effort(0.6, -0.6) # Spin right
+        time.sleep(0.5)
+        drivetrain.set_effort(-0.6, 0.6) # Spin left
+        time.sleep(0.5)
+        
+    drivetrain.stop()
+    print("Dance finished.")
+
+def drive_and_beep():
+    """Driving forward and playing a note at the same time."""
+    # Start driving forward (this is non-blocking)
+    drivetrain.set_effort(0.5, 0.5)
+    
+    # Play a long note (blocking=True) so the robot drives for the duration of the note
+    print("Driving for a whole note...")
+    buzzer.play_note("C5", "whole", blocking=True)
+    
+    drivetrain.stop()
+
+def main():
+    # Run the examples
+    simple_scale()
+    time.sleep(1)
+    
+    siren()
+    time.sleep(1)
+    
+    musical_robot()
+
+main()

XRPLib/buzzer.py

@@ -4,7 +4,6 @@
 
 import machine
 import time
-import urandom
 from machine import Timer
 
 class Buzzer:
@@ -16,9 +15,6 @@ class Buzzer:
     Supports natural notes, sharps, and flats.
     """
 
-    # Pin configuration for the buzzer
-    BUZZER_PIN = 13
-
     # Duration constants (based on a default 120 BPM tempo)
     WHOLE = 4
     HALF = 2
@@ -50,15 +46,21 @@ def get_default_buzzer(cls):
             cls._DEFAULT_BUZZER_INSTANCE = cls()
         return cls._DEFAULT_BUZZER_INSTANCE
 
-    def __init__(self, pin: int = None):
+    def __init__(self, buzzer_pin: int|str = None):
         """
         Initialize the buzzer.
 
-        :param pin: The pin number for the buzzer
-        :type pin: int
+        :param buzzer_pin: The pin number for the buzzer
+        :type buzzer_pin: int|str
         """
-        if pin is None:
-            pin = self.BUZZER_PIN
+        if buzzer_pin is not None:
+            pin = buzzer_pin
+        else:
+            if hasattr(machine.Pin.board, "BOARD_BUZZER"):
+                pin = "BOARD_BUZZER"
+            else:
+                raise Exception("No buzzer pin defined, are you sure this board has a buzzer?")
+
         self._pin = machine.Pin(pin)
         self._pwm = machine.PWM(self._pin)
         self._pwm.duty_u16(0)  # Start silent

XRPLib/defaults.py

@@ -42,5 +42,5 @@
 if hasattr(Pin.board, "SERVO_4"):
     servo_four = Servo.get_default_servo(index=4)
 
-if "NanoXRP" in implementation._machine:
+if hasattr(Pin.board, "BOARD_BUZZER"):
     buzzer = Buzzer.get_default_buzzer()