Arduino Soundlight

arduino.ino

int pin = 11;
int val;

void setup() { 
  Serial.begin(9600);
}

void loop() {
  if (Serial.available() > 0) {
    val = Serial.read();
    analogWrite(pin, val);
  }
}

sound.py

# Python 2.7 code to analyze sound volume and interface with Arduino

import pyaudio # from http://people.csail.mit.edu/hubert/pyaudio/
import serial  # from http://pyserial.sourceforge.net/
import audioop
import sys
import math

def list_devices():
    # List all audio input devices
    p = pyaudio.PyAudio()
    i = 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']
        i += 1

def arduino_soundlight():
    chunk    = 2084 # Change if too fast/slow, never less than 1024
    scale    = 50   # Change if too dim/bright
    exponent = 4    # Change if too little/too much difference between loud and quiet sounds

    # 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   = 2  
    
    p = pyaudio.PyAudio()
    stream = p.open(format = pyaudio.paInt16,
                    channels = 1,
                    rate = 44100,
                    input = True,
                    frames_per_buffer = chunk,
                    input_device_index = device)
    
    print "Starting, use Ctrl+C to stop"
    try:
        ser = serial.Serial(port='com3')
        while True:
            data  = stream.read(chunk)
            rms   = audioop.rms(data, 2)

            level = min(rms / (2.0 ** 16) * scale, 1.0) 
            level = level**exponent 
            level = int(level * 255)

            print level
            ser.write(chr(level))

    except KeyboardInterrupt:
        pass
    finally:
        print "\nStopping"
        stream.close()
        p.terminate()
        ser.close()

if __name__ == '__main__':
    #list_devices()
    arduino_soundlight()