ECE 110/120 Honors Lab Section : Music Cube

Final Report

Our project is an LED cube that is programmed to light up according to the amplitude of different wavelengths of the music

Names:

Dave Simley

Bradley Morrell

Materials Required:

Solder (60/40)

Soldering Iron

RGB LEDs

Arduino Mega / Raspberry Pi?

Weekly Journal (Oct 5):

Finalized method of signal filtration

Further discussed layout of LEDs on cube

Considering using a design that would allow a varying voltage source to control how many LEDs are lit in a column, but will likely use the simpler method of assigning each LED its own digital voltage source

Indecisive towards what type of LEDs (RGB/single color)

Plan to further research into processing the filtered signal

Will need some initial parts to test and tinker to have a better idea of the projects layout

Parts List:

Weekly Journal (Oct 12):

Signal filtration was further discussed

Decided to use analog signal filtration using resistors/capacitors, but will have to experiment with this method in order to better understand the circuit's power loss

Different methods of analog filtration were designed, but will need parts to determine what specific method to use

Updated Parts List:

Weekly Journal (Oct 17):

Picked up parts

Also discussed progress of project with the rest of the lab

• Prof Schmitz advised us to use active filters

Prof Schmitz also supplied us with two MSGEQ7 IC's (essentially is a graphic eq in a chip; just needs a bit of coding to interpret its signals), and an LED display

Weekly Journal (Oct 24):

Researched MSGEQ7, and understand its functions

• It's perfect for this project, will reduce a lot of clutter and noise with the signal interpretation

Will come back next week with algorithms to utilize the EQ7

Weekly Journal (Nov 2):

Analyzed PWM, analog, and digital outputs of Arduino for LED display

Parts to pick up:

• 3 1/2 mm audio jack
• Male to male 3 1/2 cable (aux cord)

Will use these parts to analyze how the Arduino interprets the MSGEQ7's signal

Once we understand how the Arduino interprets the signal, we will be able to plug these Ardunio-specific values into the algorithm

Weekly Journal (Nov 9):

Constructed the circuit using the MSGEQ7 (schematic taken from SparkFun datasheet)

• MSGEQ7 is powered, triggered, and read by the Arduino, reducing clutter and cost

Played music into the MSGEQ7, and used the Arduino's ReadAnalogVoltage function to display values read by the Arduino's analog input

• Code:

• void setup() {
    // put your setup code here, to run once:
    pinMode(A1,INPUT);
    pinMode(3, OUTPUT);
    Serial.begin(9600);

  }

  void loop() {
    // put your main code here, to run repeatedly:
    delay(10);
    digitalWrite(3, HIGH);
    delay(10);
    digitalWrite(3, LOW);
      int sensorValue = analogRead(A1);
     // Convert the analog reading (which goes from 0 - 1023) to a voltage (0 - 5V):
     float voltage = sensorValue * (5.0 / 1023.0);
     // print out the value you read:
     Serial.println(voltage);
  }

When music was playing, the Arduino's serial monitor displayed high voltages, and when the music was paused, the Arduino displayed low voltage

We will need to look into reducing the noise read and displayed by the Arduino (may need to look into refining the circuit design, may also need to increase volume output of the iPod)