Replace BoardButtons with direct Pin polling in demo_audio_loopback.py to avoid interrupt storms on mechanical button release

demo_audio_loopback.py

@@ -2,7 +2,6 @@ import time
 import machine
 from machine import Pin, I2S
 import board_config
-from button_util import BoardButtons
 import audio_util
 
 def play_raw_pcm(filename, channels=2, rate=16000, bits=16, volume=90):
@@ -62,16 +61,15 @@ def main():
     print("=== Dynamic Audio Loopback Utility Script ===")
     print(f"Board Detected: {board_config.BOARD_TYPE}")
     
-    # Initialize buttons
-    buttons = BoardButtons()
+    # Initialize buttons using polling Pins instead of BoardButtons class (to avoid edge-triggered interrupt storms)
+    key_pin = Pin(18, Pin.IN, Pin.PULL_UP)
+    boot_pin = Pin(0, Pin.IN, Pin.PULL_UP)
     
     # Helper to check if trigger is active
     def is_talk_trigger_active():
         if board_config.touch:
             return board_config.touch.is_touched()
-        elif buttons and buttons.key:
-            return buttons.key.is_pressed()
-        return False
+        return key_pin.value() == 0
         
     filename = "local_audio_test.pcm"
     
@@ -95,7 +93,7 @@ def main():
         print("Ready: Press and hold key/screen to record...")
         start_wait = time.ticks_ms()
         while not is_talk_trigger_active():
-            if buttons.boot.is_pressed() or time.ticks_diff(time.ticks_ms(), start_wait) > 120000:
+            if boot_pin.value() == 0 or time.ticks_diff(time.ticks_ms(), start_wait) > 120000:
                 print("Exit condition met. Deleting flag and resetting...")
                 if display:
                     display.clear(0)