lights.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from ambx.ambx import AMBX, Lights
import pyaudio # from http://people.csail.mit.edu/hubert/pyaudio/
import numpy   # from http://numpy.scipy.org/
import struct
import audioop

lights = [Lights.LEFT, Lights.RIGHT, Lights.WWLEFT, Lights.WWCENTER, Lights.WWRIGHT]
decay = 0.5


'''
http://julip.co/2012/05/arduino-python-soundlight-spectrum/
'''


def list_devices(p):
    # List all audio input devices
#    p = pyaudio.PyAudio()
    i = 0
    devNr = 0
    n = p.get_device_count()
    while i < n:
        dev = p.get_device_info_by_index(i)
        if dev['maxInputChannels'] > 0:
            print str(i)+'. '+dev['name']
            devNr = i
        i += 1
    return devNr

def arduino_soundlight(p,device=0):

    #    p = pyaudio.PyAudio()
    print "choosing device: "+str(device)+': '+pyaudio.PyAudio().get_device_info_by_index(device)['name']

    chunk      = 2**12 # Change if too fast/slow, never less than 2**11
    scale      = 10    # Change if too dim/bright
    exponent   = 1     # Change if too little/too much difference between loud and quiet sounds
    #samplerate = 44100
    samplerate = int(p.get_device_info_by_index(device)['defaultSampleRate'])
    print "samplerate: %d"%samplerate
    # CHANGE THIS TO CORRECT INPUT DEVICE
    # Enable stereo mixing in your sound card
    # to make you sound output an input
    # Use list_devices() to list all your input devices
    #device   = 14 #'dmix'

    stream = p.open(format = pyaudio.paInt16,
                    channels = 1,
                    rate = samplerate,
                    input = True,
                    frames_per_buffer = chunk,
                    input_device_index = device)

    #print "Starting, use Ctrl+C to stop"
    dev = None
    try:
        dev = AMBX(0)

        for light in lights:
            try:
                dev.set_color_rgb8(light, [255, 255, 255])
            except IOError:
                print 'USB Error'
                break

        bass_temp = 0
        mid_temp = 0
        treble_temp = 0

        rms_temp = 0;
        max_rms = 0;

        while True:
            try:
                data  = stream.read(chunk)
            except IOError:
                print 'Overflow'

            # Do FFT
            [bass, mid, treble] = calculate_levels(data, chunk, samplerate)

            # Get % volume
            rms = audioop.rms(data, 2)
            rms = rms_temp * 0.95 + 0.05 * rms # low pass filter
            #if max_rms < rms:
            #    max_rms = rms
            #else:
            #    max_rms = 0.99 * max_rms # decay the saved max volume over time

            # what kind of volumes come streamed in
            rms_min = 16
            rms_max = 1400
            scale = 5.0 + 20 * (rms-rms_min)/(rms_max-rms_min)

            # if there is no sound input, switch off lights
            if rms < 8:
                #print 'off: ', rms
                for light in lights:
                    try:
                        dev.set_color_rgb8(light, [0, 0, 0])
                    except IOError:
                        print 'USB Error'
            else:

                #print scale, max_rms


                # nice levels
                bass    = max(min(int(max(min(bass  / scale, 1.0), 0.0)**exponent*255 + decay*bass_temp     ),255),0)
                mid     = max(min(int(max(min(mid   / scale, 1.0), 0.0)**exponent*255 + decay*mid_temp      ),255),0)
                treble  = max(min(int(max(min(treble/ scale, 1.0), 0.0)**exponent*255 + decay*treble_temp   ),255),0)
                bass_temp = bass
                mid_temp = mid
                treble_temp = treble

                #print bass, mid, treble

                for light in lights:
                    try:
                        dev.set_color_rgb8(light, [bass, mid, treble])
                    except IOError:
                        print 'USB Error'

    except IndexError:
        if dev is None:
            print 'No AmbX found!'

    except KeyboardInterrupt:
        pass
    finally:
        print "…Stop"
        stream.close()
        p.terminate()
    if dev is not None:
        for light in lights:
            dev.set_color_rgb8(light, [0, 0, 0])



def calculate_levels(data, chunk, samplerate):
    # Use FFT to calculate volume for each frequency
    global MAX

    # Convert raw sound data to Numpy array
    fmt = "%dH"%(len(data)/2)
    data2 = struct.unpack(fmt, data)
    data2 = numpy.array(data2, dtype='h')

    # Apply FFT
    fourier = numpy.fft.fft(data2)
    ffty = numpy.abs(fourier[0:len(fourier)/2])/1000
    ffty1=ffty[:len(ffty)/2]        # erste hälfte
    ffty2=ffty[len(ffty)/2::]+2     # zweite hälfte +2
    ffty2=ffty2[::-1]               # umdrehen
    ffty=ffty1+ffty2                # addieren
    ffty=numpy.log(ffty)-2

    fourier = list(ffty)[4:-4]
    fourier = fourier[:len(fourier)/2]

    size = len(fourier)

    # Add up for NUM_LIGHTS lights
#     NUM_LIGHTS = 5
#     levels = [   sum(fourier[i:(i+size/NUM_LIGHTS)]) for i in xrange(0, size, size/NUM_LIGHTS)  ][:NUM_LIGHTS]
    bass = sum(fourier[:5])/(5-0)
    mid = sum(fourier[6:70])/(70-6)
    treble = sum(fourier[71:])/(size-71)

    return [bass, mid, treble]

if __name__ == '__main__':
    p = pyaudio.PyAudio()
    devNr = list_devices(p)
    arduino_soundlight(p,devNr)