import image, audio, time, array, math, ulab as np from ulab import extras, numerical SIZE = 512//4 raw_buf = None fb = image.Image(SIZE+50, SIZE, image.RGB565, copy_to_fb=True) audio.init(channels=2, frequency=16000, gain=24, 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 = pcm_buf = np.array(array.array('h', raw_buf)) raw_buf = None 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) draw_audio_bar(fb, r_lvl, 25) fb.flush() # Stop streaming audio.stop_streaming()