a3d75d007a
Adding code the NeoPixel Mini VU Meter Learn Guide. Using a QT Py RP2040, PDM mic and strip of 16 neopixels
84 lines
2.3 KiB
Python
84 lines
2.3 KiB
Python
# SPDX-FileCopyrightText: 2022 Liz Clark for Adafruit Industries
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# SPDX-License-Identifier: MIT
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import time
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import array
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import math
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import board
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import audiobusio
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import simpleio
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import neopixel
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# neopixel setup
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pixel_pin = board.A0
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pixel_num = 16
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pixels = neopixel.NeoPixel(pixel_pin, pixel_num, brightness=0.1, auto_write=False)
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# function to average mic levels
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def mean(values):
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return sum(values) / len(values)
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# function to return mic level
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def normalized_rms(values):
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minbuf = int(mean(values))
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samples_sum = sum(
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float(sample - minbuf) * (sample - minbuf)
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for sample in values
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)
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return math.sqrt(samples_sum / len(values))
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# mic setup
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mic = audiobusio.PDMIn(board.TX,
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board.A1, sample_rate=16000, bit_depth=16)
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samples = array.array('H', [0] * 160)
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# variable to hold previous mic level
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last_input = 0
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# neopixel colors
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GREEN = (0, 127, 0)
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RED = (127, 0, 0)
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YELLOW = (127, 127, 0)
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OFF = (0, 0, 0)
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# array of colors for VU meter
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colors = [GREEN, GREEN, GREEN, GREEN, GREEN, GREEN, GREEN, GREEN,
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GREEN, YELLOW, YELLOW, YELLOW, YELLOW, YELLOW, RED, RED]
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# begin with pixels off
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pixels.fill(OFF)
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pixels.show()
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while True:
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# take in audio
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mic.record(samples, len(samples))
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# magnitude holds the value of the mic level
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magnitude = normalized_rms(samples)
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# uncomment to see the levels in the REPL
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# print((magnitude,))
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# mapping the volume range (125-500) to the 16 neopixels
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# volume range is optimized for music. you may want to adjust the range
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# based on the type of audio that you're trying to show
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mapped_value = simpleio.map_range(magnitude, 125, 500, 0, 16)
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# converting the mapped range to an integer
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input_val = int(mapped_value)
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# if the mic input has changed from the last input value...
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if last_input != input_val:
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for i in range(input_val):
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# if the level is lower...
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if last_input > input_val:
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for z in range(last_input):
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# turn those pixels off
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pixels[z] = (OFF)
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# turn on pixels using the colors array
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pixels[i] = (colors[i])
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pixels.show()
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# update last_input
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last_input = input_val
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time.sleep(0.01)
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