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| 1 | +# SPDX-FileCopyrightText: 2018 John Edgar Park for Adafruit Industries |
| 2 | +# |
| 3 | +# SPDX-License-Identifier: MIT |
| 4 | + |
| 5 | +import time |
| 6 | +import math |
| 7 | +import array |
| 8 | +import audiobusio |
| 9 | +import audioio |
| 10 | +import audiocore |
| 11 | +import board |
| 12 | +from adafruit_crickit import crickit |
| 13 | + |
| 14 | +# Number of samples to read at once. |
| 15 | +NUM_SAMPLES = 160 |
| 16 | + |
| 17 | +# Remove DC bias before computing RMS. |
| 18 | +def normalized_rms(values): |
| 19 | + minbuf = int(mean(values)) |
| 20 | + samples_sum = sum( |
| 21 | + float(sample - minbuf) * (sample - minbuf) |
| 22 | + for sample in values |
| 23 | + ) |
| 24 | + |
| 25 | + return math.sqrt(samples_sum / len(values)) |
| 26 | + |
| 27 | +def mean(values): |
| 28 | + return sum(values) / len(values) |
| 29 | + |
| 30 | +mic = audiobusio.PDMIn(board.MICROPHONE_CLOCK, board.MICROPHONE_DATA, |
| 31 | + sample_rate=16000, bit_depth=16) |
| 32 | + |
| 33 | +# Record an initial sample to calibrate. Assume it's quiet when we start. |
| 34 | +samples = array.array('H', [0] * NUM_SAMPLES) |
| 35 | +mic.record(samples, len(samples)) |
| 36 | + |
| 37 | +head_servo = crickit.servo_1 |
| 38 | +head_servo.set_pulse_width_range(min_pulse=500, max_pulse=2500) |
| 39 | +head_servo.angle = 90 # center the head. |
| 40 | + |
| 41 | +# Set audio out on speaker. |
| 42 | +a = audioio.AudioOut(board.A0) |
| 43 | + |
| 44 | +# Start playing the file (in the background). |
| 45 | +def play_file(wavfile): |
| 46 | + print("Playing scream!") |
| 47 | + with open(wavfile, "rb") as f: |
| 48 | + wav = audiocore.WaveFile(f) |
| 49 | + a.play(wav) |
| 50 | + while a.playing: |
| 51 | + head_servo.angle = 60 |
| 52 | + time.sleep(.01) |
| 53 | + head_servo.angle = 120 |
| 54 | + time.sleep(.01) |
| 55 | + |
| 56 | + |
| 57 | +while True: |
| 58 | + mic.record(samples, len(samples)) |
| 59 | + magnitude = normalized_rms(samples) |
| 60 | + print(((magnitude),)) # formatting is for the Mu plotter. |
| 61 | + |
| 62 | + if magnitude < 1000: # it's quiet, do nothing. |
| 63 | + pass |
| 64 | + else: |
| 65 | + print("LOUD") |
| 66 | + head_servo.angle = 60 |
| 67 | + time.sleep(.05) |
| 68 | + head_servo.angle = 120 |
| 69 | + time.sleep(.05) |
| 70 | + head_servo.angle = 90 |
| 71 | + time.sleep(.02) |
| 72 | + play_file("scream_low.wav") |
| 73 | + head_servo.angle = 90 |
| 74 | + time.sleep(2) |
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