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

   1 # SPDX-FileCopyrightText: 2021 Phil Burgess for Adafruit Industries
   2 #
   3 # SPDX-License-Identifier: MIT
   4
   5 """
   6 AUDIO SPECTRUM LIGHT SHOW for Adafruit EyeLights (LED Glasses + Driver).
   7 Uses onboard microphone and a lot of math to react to music.
   8 """
   9
  10 from array import array
  11 from math import log
  12 from time import monotonic
  13 from supervisor import reload
  14 import board
  15 from audiobusio import PDMIn
  16 from busio import I2C
  17 import adafruit_is31fl3741
  18 from adafruit_is31fl3741.adafruit_rgbmatrixqt import Adafruit_RGBMatrixQT
  19 from rainbowio import colorwheel
  20 from ulab import numpy as np
  21 #  if using CP7 and below:
  22 from ulab.scipy.signal import spectrogram
  23 #  if using CP8 and above:
  24 #  from ulab.utils import spectrogram
  25
  26
  27 # FFT/SPECTRUM CONFIG ----
  28
  29 fft_size = 256  # Sample size for Fourier transform, MUST be power of two
  30 spectrum_size = fft_size // 2  # Output spectrum is 1/2 of FFT result
  31 # Bottom of spectrum tends to be noisy, while top often exceeds musical
  32 # range and is just harmonics, so clip both ends off:
  33 low_bin = 10  # Lowest bin of spectrum that contributes to graph
  34 high_bin = 75  # Highest bin "
  35
  36
  37 # HARDWARE SETUP ---------
  38
  39 # Manually declare I2C (not board.I2C() directly) to access 1 MHz speed...
  40 i2c = I2C(board.SCL, board.SDA, frequency=1000000)
  41
  42 # Initialize the IS31 LED driver, buffered for smoother animation
  43 #glasses = LED_Glasses(i2c, allocate=adafruit_is31fl3741.MUST_BUFFER)
  44 glasses = Adafruit_RGBMatrixQT(i2c, allocate=adafruit_is31fl3741.MUST_BUFFER)
  45
  46 glasses.show()  # Clear any residue on startup
  47 glasses.set_led_scaling(0xFF)
  48 glasses.global_current = 5  # Not too bright please
  49 glasses.enable = True
  50
  51 # Initialize mic and allocate recording buffer (default rate is 16 MHz)
  52 mic = PDMIn(board.MICROPHONE_CLOCK, board.MICROPHONE_DATA, bit_depth=16)
  53 rec_buf = array("H", [0] * fft_size)  # 16-bit audio samples
  54
  55
  56 # FFT/SPECTRUM SETUP -----
  57
  58 # To keep the display lively, tables are precomputed where each column of
  59 # the matrix (of which there are few) is the sum value and weighting of
  60 # several bins from the FFT spectrum output (of which there are many).
  61 # The tables also help visually linearize the output so octaves are evenly
  62 # spaced, as on a piano keyboard, whereas the source spectrum data is
  63 # spaced by frequency in Hz.
  64 column_table = []
  65
  66 spectrum_bits = log(spectrum_size, 2)  # e.g. 7 for 128-bin spectrum
  67 # Scale low_bin and high_bin to 0.0 to 1.0 equivalent range in spectrum
  68 low_frac = log(low_bin, 2) / spectrum_bits
  69 frac_range = log(high_bin, 2) / spectrum_bits - low_frac
  70
  71 for column in range(glasses.width):
  72     # Determine the lower and upper frequency range for this column, as
  73     # fractions within the scaled 0.0 to 1.0 spectrum range. 0.95 below
  74     # creates slight frequency overlap between columns, looks nicer.
  75     lower = low_frac + frac_range * (column / glasses.width * 0.95)
  76     upper = low_frac + frac_range * ((column + 1) / glasses.width)
  77     mid = (lower + upper) * 0.5  # Center of lower-to-upper range
  78     half_width = (upper - lower) * 0.5  # 1/2 of lower-to-upper range
  79     # Map fractions back to spectrum bin indices that contribute to column
  80     first_bin = int(2 ** (spectrum_bits * lower) + 1e-4)
  81     last_bin = int(2 ** (spectrum_bits * upper) + 1e-4)
  82     bin_weights = []  # Each spectrum bin's weighting will be added here
  83     for bin_index in range(first_bin, last_bin + 1):
  84         # Find distance from column's overall center to individual bin's
  85         # center, expressed as 0.0 (bin at center) to 1.0 (bin at limit of
  86         # lower-to-upper range).
  87         bin_center = log(bin_index + 0.5, 2) / spectrum_bits
  88         dist = abs(bin_center - mid) / half_width
  89         if dist < 1.0:  # Filter out a few math stragglers at either end
  90             # Bin weights have a cubic falloff curve within range:
  91             dist = 1.0 - dist  # Invert dist so 1.0 is at center
  92             bin_weights.append(((3.0 - (dist * 2.0)) * dist) * dist)
  93     # Scale bin weights so total is 1.0 for each column, but then mute
  94     # lower columns slightly and boost higher columns. It graphs better.
  95     total = sum(bin_weights)
  96     bin_weights = [
  97         (weight / total) * (0.8 + idx / glasses.width * 1.4)
  98         for idx, weight in enumerate(bin_weights)
  99     ]
 100     # List w/five elements is stored for each column:
 101     # 0: Index of the first spectrum bin that impacts this column.
 102     # 1: A list of bin weights, starting from index above, length varies.
 103     # 2: Color for drawing this column on the LED matrix. The 225 is on
 104     #    purpose, providing hues from red to purple, leaving out magenta.
 105     # 3: Current height of the 'falling dot', updated each frame
 106     # 4: Current velocity of the 'falling dot', updated each frame
 107     column_table.append(
 108         [
 109             first_bin - low_bin,
 110             bin_weights,
 111             colorwheel(225 * column / glasses.width),
 112             glasses.height,
 113             0.0,
 114         ]
 115     )
 116 # print(column_table)
 117
 118
 119 # MAIN LOOP -------------
 120
 121 dynamic_level = 10  # For responding to changing volume levels
 122 frames, start_time = 0, monotonic()  # For frames-per-second calc
 123
 124 while True:
 125     # The try/except here is because VERY INFREQUENTLY the I2C bus will
 126     # encounter an error when accessing the LED driver, whether from bumping
 127     # around the wires or sometimes an I2C device just gets wedged. To more
 128     # robustly handle the latter, the code will restart if that happens.
 129     try:
 130         mic.record(rec_buf, fft_size)  # Record batch of 16-bit samples
 131         samples = np.array(rec_buf)  # Convert to ndarray
 132         # Compute spectrogram and trim results. Only the left half is
 133         # normally needed (right half is mirrored), but we trim further as
 134         # only the low_bin to high_bin elements are interesting to graph.
 135         spectrum = spectrogram(samples)[low_bin : high_bin + 1]
 136         # Linearize spectrum output. spectrogram() is always nonnegative,
 137         # but add a tiny value to change any zeros to nonzero numbers
 138         # (avoids rare 'inf' error)
 139         spectrum = np.log(spectrum + 1e-7)
 140         # Determine minimum & maximum across all spectrum bins, with limits
 141         lower = max(np.min(spectrum), 4)
 142         upper = min(max(np.max(spectrum), lower + 6), 20)
 143
 144         # Adjust dynamic level to current spectrum output, keeps the graph
 145         # 'lively' as ambient volume changes. Sparkle but don't saturate.
 146         if upper > dynamic_level:
 147             # Got louder. Move level up quickly but allow initial "bump."
 148             dynamic_level = upper * 0.7 + dynamic_level * 0.3
 149         else:
 150             # Got quieter. Ease level down, else too many bumps.
 151             dynamic_level = dynamic_level * 0.5 + lower * 0.5
 152
 153         # Apply vertical scale to spectrum data. Results may exceed
 154         # matrix height...that's OK, adds impact!
 155         #data = (spectrum - lower) * (7 / (dynamic_level - lower))
 156         data = (spectrum - lower) * ((glasses.height + 2) / (dynamic_level - lower))
 157
 158         for column, element in enumerate(column_table):
 159             # Start BELOW matrix and accumulate bin weights UP, saves math
 160             first_bin = element[0]
 161             column_top = glasses.height + 1
 162             for bin_offset, weight in enumerate(element[1]):
 163                 column_top -= data[first_bin + bin_offset] * weight
 164
 165             if column_top < element[3]:  #       Above current falling dot?
 166                 element[3] = column_top - 0.5  # Move dot up
 167                 element[4] = 0  #                and clear out velocity
 168             else:
 169                 element[3] += element[4]  #      Move dot down
 170                 element[4] += 0.2  #             and accelerate
 171
 172             column_top = int(column_top)  #      Quantize to pixel space
 173             for row in range(column_top):  #     Erase area above column
 174                 glasses.pixel(column, row, 0)
 175             for row in range(column_top, glasses.height):  #  Draw column
 176                 glasses.pixel(column, row, element[2])
 177             glasses.pixel(column, int(element[3]), 0xE08080)  # Draw peak dot
 178
 179         glasses.show()  # Buffered mode MUST use show() to refresh matrix
 180
 181         frames += 1
 182         # print(frames / (monotonic() - start_time), "FPS")
 183
 184     except OSError:  # See "try" notes above regarding rare I2C errors.
 185         print("Restarting")
 186         reload()