Update sound meter code to work with CPB and CPX

adafruit_circuitplayground/circuit_playground_base.py

@@ -39,6 +39,7 @@
 import math
 import array
 import time
+import os
 
 try:
  import audiocore
@@ -78,6 +79,9 @@ class CircuitPlaygroundBase: # pylint: disable=too-many-public-methods
 
  _audio_out = None
 
+ # Circuit Playground specific board names as found in os.uname().machine
+ _CP_TYPES = ("Bluefruit", "Express")
+
  def __init__(self):
  self._a = digitalio.DigitalInOut(board.BUTTON_A)
  self._a.switch_to_input(pull=digitalio.Pull.DOWN)
@@ -138,6 +142,52 @@ def __init__(self):
  self._detect_taps = 1
  self.detect_taps = 1
 
+ @property
+ def circuit_playground_type(self):
+ """The Circuit Playground board type currently running the library. Returns the board name
+ shortened to the specific type, e.g. ``Express`` or ``Bluefruit``.
+
+ The following example prints the board type to the serial console.
+
+ To use with the Circuit Playground Express or Bluefruit:
+
+ .. code-block:: python
+
+ from adafruit_circuitplayground import cp
+
+ print(cp.circuit_playground_type)
+ """
+ board_name = os.uname().machine
+ for board_type in self._CP_TYPES:
+ if board_type in board_name:
+ return board_type
+ raise ValueError("Board unsupported by this library.")
+
+ def circuit_playground_is_type(self, is_type):
+ """Checks whether the board is the specified type of Circuit Playground, using the board
+ name shortened to the specific type, e.g. ``Express`` or ``Bluefruit``.
+
+ To use with the Circuit Playground Express or Bluefruit:
+
+ The following example prints the board type to the serial console, if the board type is a
+ Circuit Playground Express. It does nothing if the board is not a CPX. Change ``Express``
+ to ``Bluefruit`` to print the board type to the serial console, if the board type is a
+ Circuit Playground Bluefruit.
+
+ .. code-block:: python
+
+ from adafruit_circuitplayground import cp
+
+ if cp.circuit_playground_is_type("Express"):
+ print(cp.circuit_playground_type)
+
+ """
+ if is_type not in self._CP_TYPES:
+ raise ValueError(
+ "Valid Circuit Playground boards are {}".format(self._CP_TYPES)
+ )
+ return self.circuit_playground_type == is_type
+
  @property
  def detect_taps(self):
  """Configure what type of tap is detected by ``cp.tapped``. Use ``1`` for single-tap

examples/circuitplayground_sound_meter.py

@@ -3,8 +3,8 @@
 to see the NeoPixels light up!"""
 import array
 import math
-import board
 import audiobusio
+import board
 from adafruit_circuitplayground import cp
 
 
@@ -27,23 +27,32 @@ def normalized_rms(values):
  )
 
 
-mic = audiobusio.PDMIn(
- board.MICROPHONE_CLOCK, board.MICROPHONE_DATA, sample_rate=16000, bit_depth=16
-)
+# Check to see if the board type is a Circuit Playground Express, and, if so, run the following:
+if cp.circuit_playground_is_type("Express"):
+ mic = audiobusio.PDMIn(
+ board.MICROPHONE_CLOCK, board.MICROPHONE_DATA, sample_rate=16000, bit_depth=16
+ )
 
-samples = array.array("H", [0] * 160)
-mic.record(samples, len(samples))
-input_floor = normalized_rms(samples) + 10
+ samples = array.array("H", [0] * 160)
+ mic.record(samples, len(samples))
+ input_floor = normalized_rms(samples) + 10
+# If it is not, run the following:
+else:
+ input_floor = cp.sound_level + 10
 
 # Lower number means more sensitive - more LEDs will light up with less sound.
 sensitivity = 500
 input_ceiling = input_floor + sensitivity
 
 peak = 0
 while True:
- mic.record(samples, len(samples))
- magnitude = normalized_rms(samples)
- print((magnitude,))
+ if cp.circuit_playground_is_type("Express"): # Circuit Playground Express
+ mic.record(samples, len(samples))
+ magnitude = normalized_rms(samples)
+ else: # Not CPX
+ magnitude = cp.sound_level
+
+ print((magnitude,)) # Printed as a tuple for the Mu plotter.
 
  c = log_scale(
  constrain(magnitude, input_floor, input_ceiling),