Adding CP example code and audio files

Author: BlitzCityDIY

Audio_BFF/audio_files - for SD card/adabot.wav

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+# SPDX-FileCopyrightText: 2023 ladyada for Adafruit Industries
+#
+# SPDX-License-Identifier: MIT
+
+# Demo audio player that plays random wav files from internal storage or
+# SD card. Default pinout matches the Audio BFF for QT Py S2, S3 and RP2040
+
+import os
+import time
+import audiocore
+import board
+import audiobusio
+import audiomixer
+import adafruit_sdcard
+import storage
+import digitalio
+import random
+
+card_cs = digitalio.DigitalInOut(board.A0)
+card_cs.direction = digitalio.Direction.INPUT
+card_cs.pull = digitalio.Pull.UP
+sdcard = None
+
+DATA = board.A1
+LRCLK = board.A2
+BCLK = board.A3
+audio = audiobusio.I2SOut(BCLK, LRCLK, DATA)
+mixer = None
+
+button = digitalio.DigitalInOut(board.BUTTON)
+button.switch_to_input(pull=digitalio.Pull.UP)
+
+wave_files = []
+for filename in sorted(os.listdir("/")):
+    filename = filename.lower()
+    if filename.endswith(".wav") and not filename.startswith("."):
+        wave_files.append(filename)
+
+while True:
+    if not sdcard:
+        try:
+            sdcard = adafruit_sdcard.SDCard(board.SPI(), card_cs)
+            vfs = storage.VfsFat(sdcard)
+            storage.mount(vfs, "/sd")
+            print("Mounted SD card")
+            wave_files = ["/"+file for file in os.listdir('/') if file.endswith('.wav')]
+            wave_files += ["/sd/"+file for file in os.listdir('/sd') if file.endswith('.wav')]
+            print(wave_files)
+        except OSError:
+            pass
+
+    if not button.value:
+        if mixer and mixer.voice[0].playing:
+            print("stopping")
+            mixer.voice[0].stop()
+            if wavefile:
+                wavefile.close()
+        else:
+            name = random.choice(wave_files)
+            print("playing", name)
+            wavefile = open(name, "rb")
+            wave = audiocore.WaveFile(wavefile)
+            mixer = audiomixer.Mixer(voice_count=1,
+                                     sample_rate=wave.sample_rate,
+                                     channel_count=wave.channel_count,
+                                     bits_per_sample=wave.bits_per_sample,
+                                     samples_signed=True)
+            mixer.voice[0].level = 0.1
+            audio.play(mixer)
+            mixer.voice[0].play(wave)
+
+        while not button.value:
+            pass