import audiobusio

import board

import digitalio

import array

import time

import math

trigger = digitalio.DigitalInOut(board.D4)

trigger.switch_to_output(True)

def mean(values):

return sum(values) / len(values)

def normalized_rms(values):

minbuf = int(mean(values))

samples_sum = sum(float(sample - minbuf) * (sample - minbuf) for sample in values)

return math.sqrt(samples_sum / len(values))

# signed 16 bit

s16 = array.array("H", [0] * 10000)

pdm = audiobusio.PDMIn(clock_pin=board.D11, data_pin=board.D12, sample_rate=24000, bit_depth=16)

print("starting read")

trigger.value = False

count = pdm.record(s16, len(s16))

trigger.value = True

print("read done")

print("recorded {} samples".format(count))

for v in s16[:count]:

print(v)

magnitude = normalized_rms(s16)

print("magnitude", magnitude)

print("count", count)

print("done")