examples/noise-amps-at-freqs.py

   1 import ST7735
   2 from PIL import Image, ImageDraw
   3 from enviroplus.noise import Noise
   4
   5 print("""noise-amps-at-freqs.py - Measure amplitude from specific frequency bins
   6
   7 This example retrieves the median amplitude from 3 user-specified frequency ranges and plots them in Blue, Green and Red on the Enviro+ display.
   8
   9 As you play a continuous rising tone on your phone, you should notice peaks that correspond to the frequency entering each range.
  10
  11 Press Ctrl+C to exit!
  12
  13 """)
  14
  15 noise = Noise()
  16
  17 disp = ST7735.ST7735(
  18     port=0,
  19     cs=ST7735.BG_SPI_CS_FRONT,
  20     dc=9,
  21     backlight=12,
  22     rotation=90)
  23
  24 disp.begin()
  25
  26 img = Image.new('RGB', (disp.width, disp.height), color=(0, 0, 0))
  27 draw = ImageDraw.Draw(img)
  28
  29
  30 while True:
  31     amps = noise.get_amplitudes_at_frequency_ranges([
  32         (100, 200),
  33         (500, 600),
  34         (1000, 1200)
  35     ])
  36     amps = [n * 32 for n in amps]
  37     img2 = img.copy()
  38     draw.rectangle((0, 0, disp.width, disp.height), (0, 0, 0))
  39     img.paste(img2, (1, 0))
  40     draw.line((0, 0, 0, amps[0]), fill=(0, 0, 255))
  41     draw.line((0, 0, 0, amps[1]), fill=(0, 255, 0))
  42     draw.line((0, 0, 0, amps[2]), fill=(255, 0, 0))
  43
  44     disp.display(img)