circuitPython/PDMmic.py

   1 import audiobusio
   2 import math
   3 import board
   4 import array
   5 import simpleio
   6 import time
   7
   8 def mean(values):
   9     return sum(values)/len(values)
  10
  11 def normalized_rms(values):
  12     minbuf=int(mean(values))
  13     samples_sum=sum(float(sample-minbuf)*(sample-minbuf)
  14                     for sample in values)
  15
  16     return math.sqrt(samples_sum/len(values))
  17
  18 #mic setup
  19 mic=audiobusio.PDMIn(board.D8,board.D9,sample_rate=16000, bit_depth=16)
  20 samples=array.array('H',[0]*160)
  21
  22 #last_input=0
  23
  24 while True:
  25     mic.record(samples,len(samples))
  26     magnitude=normalized_rms(samples)
  27     #print((magnitude,))
  28     mapped_value=simpleio.map_range(magnitude, 125, 500, 0, 16)
  29     input_val=int(mapped_value)
  30     print(input_val)