openmv/scripts/examples/Arduino/Nano 33 BLE Sense/03-Audio/audio_fft.py
2021-01-07 00:44:59 +02:00

57 lines
1.7 KiB
Python

import image, audio, time, array, math, ulab as np
from ulab import extras, numerical
CHANNELS = 1
SIZE = 256//(2*CHANNELS)
raw_buf = None
fb = image.Image(SIZE+50, SIZE, image.RGB565, copy_to_fb=True)
audio.init(channels=CHANNELS, frequency=16000, gain_db=80, highpass=0.9883)
def audio_callback(buf):
# NOTE: do Not call any function that allocates memory.
global raw_buf
if (raw_buf == None):
raw_buf = buf
# Start audio streaming
audio.start_streaming(audio_callback)
def draw_fft(img, fft_buf):
fft_buf = (fft_buf / max(fft_buf)) * SIZE
fft_buf = np.vector.log10(fft_buf + 1) * 20
color = (0xFF, 0x0F, 0x00)
for i in range(0, SIZE):
img.draw_line(i, SIZE, i, SIZE-int(fft_buf[i]), color, 1)
def draw_audio_bar(img, level, offset):
blk_size = SIZE//10
color = (0xFF, 0x00, 0xF0)
blk_space = (blk_size//4)
for i in range(0, int(round(level/10))):
fb.draw_rectangle(SIZE+offset, SIZE - ((i+1)*blk_size) + blk_space, 20, blk_size - blk_space, color, 1, True)
while (True):
if (raw_buf != None):
pcm_buf = np.array(array.array('h', raw_buf))
raw_buf = None
if CHANNELS == 1:
fft_buf = extras.spectrogram(pcm_buf)
l_lvl = int((numerical.mean(abs(pcm_buf)) / 32768)*100)
else:
fft_buf = extras.spectrogram(pcm_buf[0::2])
l_lvl = int((numerical.mean(abs(pcm_buf[1::2])) / 32768)*100)
r_lvl = int((numerical.mean(abs(pcm_buf[0::2])) / 32768)*100)
fb.clear()
draw_fft(fb, fft_buf)
draw_audio_bar(fb, l_lvl, 0)
if CHANNELS == 2:
draw_audio_bar(fb, r_lvl, 25)
fb.flush()
# Stop streaming
audio.stop_streaming()