circuitPython/waterfall_visualizer/CircuitPython 7.x/code.py

   1 # SPDX-FileCopyrightText: 2021 Liz Clark for Adafruit Industries
   2 #
   3 # SPDX-License-Identifier: MIT
   4
   5 '''Adapted from the FFT Example: Waterfall Spectrum Analyzer
   6 by Jeff Epler
   7 https://learn.adafruit.com/ulab-crunch-numbers-fast-with-circuitpython/overview '''
   8
   9 import array
  10 import board
  11 import audiobusio
  12 import busio
  13 from ulab import numpy as np
  14 from ulab.scipy.signal import spectrogram
  15 import adafruit_is31fl3741
  16 from adafruit_is31fl3741.adafruit_rgbmatrixqt import Adafruit_RGBMatrixQT
  17
  18 #  Manually declare I2c (not board.I2C()) to access 1 MHz speed for
  19 i2c = busio.I2C(board.SCL, board.SDA, frequency=1000000)
  20 #  Declare is31 w/buffering preferred (low RAM will fall back on unbuffered)
  21 is31 = Adafruit_RGBMatrixQT(i2c, allocate=adafruit_is31fl3741.PREFER_BUFFER)
  22 #  In buffered mode, MUST use show() to refresh matrix (see line 94)
  23
  24 #  brightness for the RGBMatrixQT
  25 #  set to about 20%
  26 is31.set_led_scaling(0x19)
  27 is31.global_current = 0x03
  28 is31.enable = True
  29
  30 #  array of colors for the LEDs
  31 #  goes from purple to red
  32 #  gradient generated using https://colordesigner.io/gradient-generator
  33 heatmap = [0xb000ff,0xa600ff,0x9b00ff,0x8f00ff,0x8200ff,
  34            0x7400ff,0x6500ff,0x5200ff,0x3900ff,0x0003ff,
  35            0x0003ff,0x0047ff,0x0066ff,0x007eff,0x0093ff,
  36            0x00a6ff,0x00b7ff,0x00c8ff,0x00d7ff,0x00e5ff,
  37            0x00e0ff,0x00e6fd,0x00ecf6,0x00f2ea,0x00f6d7,
  38            0x00fac0,0x00fca3,0x00fe81,0x00ff59,0x00ff16,
  39            0x00ff16,0x45ff08,0x62ff00,0x78ff00,0x8bff00,
  40            0x9bff00,0xaaff00,0xb8ff00,0xc5ff00,0xd1ff00,
  41            0xedff00,0xf5eb00,0xfcd600,0xffc100,0xffab00,
  42            0xff9500,0xff7c00,0xff6100,0xff4100,0xff0000,
  43            0xff0000,0xff0000]
  44
  45 #  size of the FFT data sample
  46 fft_size = 64
  47
  48 #  setup for onboard mic
  49 mic = audiobusio.PDMIn(board.MICROPHONE_CLOCK, board.MICROPHONE_DATA,
  50                        sample_rate=16000, bit_depth=16)
  51
  52 #  use some extra sample to account for the mic startup
  53 samples_bit = array.array('H', [0] * (fft_size+3))
  54
  55 #  sends visualized data to the RGB matrix with colors
  56 def waves(data, y):
  57     offset = max(0, (13-len(data))//2)
  58
  59     for x in range(min(13, len(data))):
  60         is31.pixel(x+offset, y, heatmap[int(data[x])])
  61
  62 # main loop
  63 def main():
  64     #  value for audio samples
  65     max_all = 10
  66     #  variable to move data along the matrix
  67     scroll_offset = 0
  68     #  setting the y axis value to equal the scroll_offset
  69     y = scroll_offset
  70
  71     while True:
  72         #  record the audio sample
  73         mic.record(samples_bit, len(samples_bit))
  74         #  send the sample to the ulab array
  75         samples = np.array(samples_bit[3:])
  76         #  creates a spectogram of the data
  77         spectrogram1 = spectrogram(samples)
  78         # spectrum() is always nonnegative, but add a tiny value
  79         # to change any zeros to nonzero numbers
  80         spectrogram1 = np.log(spectrogram1 + 1e-7)
  81         spectrogram1 = spectrogram1[1:(fft_size//2)-1]
  82         #  sets range of the spectrogram
  83         min_curr = np.min(spectrogram1)
  84         max_curr = np.max(spectrogram1)
  85         #  resets values
  86         if max_curr > max_all:
  87             max_all = max_curr
  88         else:
  89             max_curr = max_curr-1
  90         min_curr = max(min_curr, 3)
  91         # stores spectrogram in data
  92         data = (spectrogram1 - min_curr) * (51. / (max_all - min_curr))
  93         # sets negative numbers to zero
  94         data = data * np.array((data > 0))
  95         #  resets y
  96         y = scroll_offset
  97         #  runs waves to write data to the LED's
  98         waves(data, y)
  99         #  updates scroll_offset to move data along matrix
 100         scroll_offset = (y + 1) % 9
 101         #  writes data to the RGB matrix
 102         is31.show()
 103
 104 main()