Those TAOS sensors look promising, I checked mouser and there are a lot to choose from and they are cheaper than I thought they would be.

I was hoping to leave a computer out of the equation so hopefully I can get something working with just the arduino.

If anyone has suggestions on some multi color led lights to use that would be helpful too.  I was hoping to buy some of the GE g-35 christmas lights but can't find them anymore, the only other serial communication ready lights I found were $5 a piece. 

I want to use something to sense what the majority of the color on at tv screen is and have ambient lighting throughout the room reproduce that color.  I'm new to arduino but it doesn't seem like video processing is an option.  What kind of sensor that arduino could support would work best?

[setup]

I did a little research into measuring tempo, aka BPM, and found it to be a very non exact science.  Depending on what note being played in a song determines the beat varies.  You could make a filter to focus on the note for a particular song that defines the beat but that note and therefore the frequency the filter is looking at would need to change for different songs.  Using the the low pass filter for bass seems to work for giving you a general idea of the tempo of most songs.

I wrote some code to calculate the BPM though I still haven't thought of a good use for it, putting extra 7-segment displays to use is the best thing I thought of.  It is not accurate until 60 seconds of music has played, it is beats per minute after all, and it tracks accurately after that.  Music does change tempo during a single song so having a single BPM would still just be an average.  Anyways, here's some more code to look at for anyone interested.

/*  Bass Detection Basic with BPM
-Perform actions based on bass
-calculates a running average BPM
 
      Created by: Matthew Kachur
*/

int tic = 0;
int Bass = 0;
int Bmin = 0;
int Bmax = 0;
int Beat = 0;
int BeatTot = 0;
int BPS = 0;
int BPMray[60];
int BPM = 0;
int BPMt = 0;
long pmil = 0;

void setup() {
  pinMode(A0, INPUT);
}

void loop() {
  //Loop counter, and auto correcting
  ++tic;
  if (tic > 200) {  //determines rate of correction
    ++Bmin;
    --Bmax;
    tic = 0;
  }
  if (millis() - pmil >= 1000) {
    pmil = millis();
    ++BPMt;
    BeatTot -= BPMray[BPMt];
    BPMray[BPMt] = BPS;
    BeatTot += BPMray[BPMt];
    BPM = BeatTot/60;
    BPS = 0;
    if (BPMt >= 60){
      BPMt = 0;
    }
  }
  
  //Order of calculations is important!!
  Bmin = min(Bmin, Bass);
  
  Bass = analogRead(A0) - Bmin;
  
  Bmax = max(Bmax, Bass);
  
  //Series of if statements to control actions
  //according to bass level
  if (Bass > 0.5 * Bmax) {
    //Do something
    if (Bass > 0.7 * Bmax) {
      Beat = 1;
      //Do something more
      if (Bass > 0.9 * Bmax) {
        //Do something Crazy!
      }
    }
  }
  if (Bass < 0.5 * Bmax && Beat == 1) {
    Beat = 0;
    ++BPS;
  }
}

Hi,
do you know if i could do the same thing --> control led lights using a playlist of say 3 songs in max/msp and then sending it to arduino to change the led colors?

I'm not familiar with max/msp, I just got Arduino 2 weeks ago.  Any analog signal will work with this program regardless of the source.  To get bass isolated you would still need to create a filter before the signal is put into the Arduino since the code only performs actions based on amplitude and doesn't do any filtering.  I looked up max/msp and plan to mess with it in the near future so if you still have trouble I may be of more assistance later.

Unfortunately not actually beat detection, I was kinda hoping for some true 'beat detection' code which is extremely difficult.

Yes, but I couldn't think of any good reason to actually detect the beat pattern of music, if you want to play different songs or very dynamic music a program that detected beats would not be very useful.  This program allows for rapid change in music intensity and rhythm and will still perform actions based on the bass hits as long as you have a halfway decent filter. 

I can add a few lines of code to estimate BPM if you were looking for something like that.  If you have an awesome project idea that requires being able to estimate the upcoming beats in music before they are played then you can let me know and maybe it will inspire me to take up the coding challenge, for the projects I have in mind though this is all I need.

Hey Alcafuz,

I just finished writing code for using an electret with an Arduino.  I posted my code in the topic about music detection.  I use a 386 to amplify the signal first and it is just enough, more amplification would be better but would also be more expensive, so I made the code do the work.  Let me know if you have any questions about it.  Also when I was looking up specs on electret microphones most suggested low voltages around 2V so I used the 3.3V power with a resistor to power it, I don't know what my specific model mine is, it just came with a box of random electronics, but it seems to work well.

[setup]

You're welcome Bean.  And now for the microphone specific code.

I used a cheap electret microphone for my testing because most people, including myself, will use them for sound responsive projects, if you have a high quality microphone you can probably use the original code I posted.  This code is designed to make any project bounce, blink, or explode to music(or other noise) for the lowest cost and with minimal effort.

I used the exact same filter and amplifier circuit from before, I just put the microphone output to the audio connection instead of the 3.5mm cable audio signal.  The louder the music the better but it works at surprisingly low levels.  This code might not be as clear as the last one so let me know if there are any confusing parts.  It still auto corrects for volume and even has a built in feature to get your project dancing back on beat as fast as possible even if someone lights off some firecrackers right next to your microphone.

I had to search how to hook up an electret microphone so to save anyone some trouble I'll explain how I did it.  The legs that looks like it has multiple internal connections going to it goes to ground only.  The other leg gets one resistor(2.2k) to power(3.3V) AND a capacitor(.047uF) and resistor(10k) in series going to ground, the capacitor connects to the microphone leg.  The output of the microphone is taken from the shared leg between the capacitor and resistor in series.  I don't remember exactly why I chose the values I did, but I remember it wasn't very important, so anything close should work, if you know why to choose the values then yours will work even better.



... I forgot the code.

/*  Musical Light Show for microphones(cheap ones)

-Lights up LEDs based on music input; can be easily
 adapted to do any action along with music
 
-Specially designed for inexpensive microphones, perfect
 for your next music sensitive costume or artwork!
 
      Created by: Matthew Kachur
*/

int tic = 0;
int Bass = 0;
int Treb = 0;
int Bdelay = 0;
int Tdelay = 0;
int Bmin = 0;
int Tmin = 0;
int Bmax = 0;
int Tmax = 0;
int B = 0;
int T = 0;
int Brange = 0;
int Trange = 0;
int Hmic = 0;
int Lmic = 0;

void setup() {
  pinMode(A0, INPUT);
  pinMode(A1, INPUT);
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  //Light delays, loop counter, and auto correcting
  ++Bdelay;
  ++Tdelay;
  ++tic;
  
  if (tic > 1000) {  //rate of music level correction
    ++Bmin;
    ++Tmin;
    --Bmax;
    --Tmax;
    tic = 0;
    Serial.println(analogRead(A1));
  }
  
  //Order of calculations is important!!
  Bmin = min(Bmin, Bass);
  Tmin = min(Tmin, Treb);
  
  Bass = analogRead(A0) - Bmin;
  Treb = analogRead(A1) - Tmin;
  
  Bmax = max(Bmax, Bass);
  Tmax = max(Tmax, Treb);
  
  //puts you back in range after a loud noise or anti-noise? is picked up
  if (Hmic > 10000 || Lmic > 10000) {
    Bmax = (analogRead(A0) / 2) + 10;
    Bmin = (analogRead(A0) / 2) - 5;
    Tmax = (analogRead(A1) / 2) + 10;
    Tmin = (analogRead(A1) / 2) - 5;
    Hmic = 0;
    Lmic = 0;
  }
  
  //makes up for small changes in microphone output at low volumes
  Brange = Bmax - Bmin;
  B = Bass - Bmin;
  Trange = Tmax - Tmin;
  T = Treb - Tmin;
  
  //Series of if statements to control actions
  //according to bass level
  if (B > 0.5 * Brange) {
    digitalWrite(2, HIGH);
    if (B > 0.6 * Brange) {
      digitalWrite(3, HIGH);
      if (B > 0.7 * Brange) {
        digitalWrite(4, HIGH);
        Lmic = 0;
        if (B > 0.8 * Brange) {
          digitalWrite(5, HIGH);
          if (B > 0.85 * Brange) {
            digitalWrite(6, HIGH);
            if (B > 0.9 * Brange) {
              digitalWrite(7, HIGH);
              ++Hmic;
              if (B > 0.95 * Brange) {
                digitalWrite(8, HIGH);
                if (B > 0.99 * Brange) {
                  digitalWrite(9, HIGH);
                }
              }
            }
          }
        }
      }
    }
  }
  if (B < 0.5 * Brange) {
    Hmic = 0;
    ++Lmic;
  }
  //Bass lights refresh rate
  if (Bdelay > 20) {
    digitalWrite(2, LOW);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
    digitalWrite(5, LOW);
    digitalWrite(6, LOW);
    digitalWrite(7, LOW);
    digitalWrite(8, LOW);
    digitalWrite(9, LOW);
    Bdelay = 0;
  }
  
  //Determines if a high pitch instrument twankled and lights up LEDs
  if (T > 0.75 * Trange) {
    digitalWrite(11, HIGH);
    if (T > 0.9 * Trange) {
      digitalWrite(12, HIGH);
    }
  }
  //Trebele lights refresh rate
  if (Tdelay > 30) {
    digitalWrite(11, LOW);
    digitalWrite(12, LOW);
    Tdelay = 0;
  }
}

[setup]

This is my first Arduino project, it is still a work in progress.  I finished the basic core of the code and saw there was a good demand for something like this and nothing good out there, so here it is.  It should be VERY easy to adapt this to any project that involves music activated features.  I created a chopped down version of my code to show the basic concept, I'll also include the code for my testing display at the bottom.

I used two LM386 chips to filter and amplify bass and treble out of a signal that I tapped out of a 3.5mm audio extension cable, if more detail on that is desired let me know.  I feed the output of the 386's to analog inputs and the Arduino outputs digital I/O power to my LEDs.  The color LEDs show bass while the two 7-segment LEDs display high pitch treble.

Also if anyone knows where I could still find some GE g-35 color effects lights or could recommend some other LEDs ready for serial communication that would be great, thanks.


I gave up on embedding the youtube video so I just put the url and then... magic.

The most basic code that will work, it won't do anything per say, but it knows what your bass is up to.

/*  Bass Detection Basic
-Perform actions based on bass

     Created by: Matthew Kachur
*/

int tic = 0;
int Bass = 0;
int Bmin = 0;
int Bmax = 0;

void setup() {
  pinMode(A0, INPUT);
}

void loop() {
  //Loop counter, and auto correcting
  ++tic;
  if (tic > 200) {  //determines rate of correction
    ++Bmin;
    --Bmax;
    tic = 0;
  }
  
  //Order of calculations is important!!
  Bmin = min(Bmin, Bass);
  
  Bass = analogRead(A0) - Bmin;
  
  Bmax = max(Bmax, Bass);
  
  //Series of if statements to control actions
  //according to bass level
  if (Bass > 0.5 * Bmax) {
    //Do something
    if (Bass > 0.7 * Bmax) {
      //Do something more
      if (Bass > 0.9 * Bmax) {
        //Do something Crazy!
      }
    }
  }
}

Pictures of my breadboarding skills, the microphone was not used for anything, I'm finishing up code designed for use with a mic soon.




The code running on my board.

/*  Musical Light Show
-Lights up LEDs based on music input; can be easily
adapted to do any action along with music

     Created by: Matthew Kachur
*/

int tic = 0;
int Bass = 0;
int Treb = 0;
int Bdelay = 0;
int Tdelay = 0;
int Bmin = 0;
int Tmin = 0;
int Bmax = 0;
int Tmax = 0;

void setup() {
  pinMode(A0, INPUT);
  pinMode(A1, INPUT);
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
}

void loop() {
  //Light delays, loop counter, and auto correcting
  ++Bdelay;
  ++Tdelay;
  ++tic;
  if (tic > 200) {  //rate of music level correction
    ++Bmin;
    ++Tmin;
    --Bmax;
    --Tmax;
    tic = 0;
  }
  
  //Order of calculations is important!!
  Bmin = min(Bmin, Bass);
  Tmin = min(Tmin, Treb);
  
  Bass = analogRead(A0) - Bmin;
  Treb = analogRead(A1) - Tmin;
  
  Bmax = max(Bmax, Bass);
  Tmax = max(Tmax, Treb);
  
  //Series of if statements to control actions
  //according to bass level
  if (Bass > 0.5 * Bmax) {
    digitalWrite(2, HIGH);
    if (Bass > 0.6 * Bmax) {
      digitalWrite(3, HIGH);
      if (Bass > 0.7 * Bmax) {
        digitalWrite(4, HIGH);
        if (Bass > 0.8 * Bmax) {
          digitalWrite(5, HIGH);
          if (Bass > 0.85 * Bmax) {
            digitalWrite(6, HIGH);
            if (Bass > 0.9 * Bmax) {
              digitalWrite(7, HIGH);
              if (Bass > 0.95 * Bmax) {
                digitalWrite(8, HIGH);
                if (Bass > 0.99 * Bmax) {
                  digitalWrite(9, HIGH);
                }
              }
            }
          }
        }
      }
    }
  }
  //Bass lights refresh rate
  if (Bdelay > 20) {
    digitalWrite(2, LOW);
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
    digitalWrite(5, LOW);
    digitalWrite(6, LOW);
    digitalWrite(7, LOW);
    digitalWrite(8, LOW);
    digitalWrite(9, LOW);
    Bdelay = 0;
  }
  
  //Determines if a high pitch instrument twankled and lights up LEDs
  if (Treb > 0.7 * Tmax) {
    digitalWrite(11, HIGH);
    if (Treb > 0.9 * Tmax) {
      digitalWrite(12, HIGH);
    }
  }
  //Trebele lights refresh rate
  if (Tdelay > 30) {
    digitalWrite(11, LOW);
    digitalWrite(12, LOW);
    Tdelay = 0;
  }
}