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[dai3504]

EDIT: I was actually able to solve my problem by moving the 10k resistors to the gate of the MOSFETs instead of the Drain.

Hello everyone, I am working on a project that makes an LED Strip respond to music using the MSGEQ7 chip. Forgive me if this a foolish question but I am having an issue where every other segment of the led strip is always on and unresponsive. (i.e. only half of the strip is blinking to the music)

I am using these LED Strips (HML 5M SMD 3528 Flexible LED RGB Strip): http://www.gearbest.com/led-strips/pp_1 ... tml?wid=21

I have followed this guide: http://www.instructables.com/id/Blinkin ... y-of-Musi/

I followed this fritzing diagram:



except that I have an external 12V 5 A DC power supply plugged into the power rail with the MOSFETs and the 12V lead of the led strip pluged into the positive terminal of that power supply.

I don't think my strips are faulty because they behave normally when I use the IR controller that they came with as opposed to my arduino.

Here is the code I was testing with:

Code: Select all

/* David Wang
   Code that takes audio input from a 3.5mm cable
   and flashes an LED strip based on the frequency
   of the music.

   HUGE thanks to the arduino community
   If you see your code here, I owe you my gratitude

*/
// MODIFY SETTINGS TO WHAT EVER WORKS BEST FOR YOU!

int analogPin = 0; // MSGEQ7 OUT
int strobePin = 2; // MSGEQ7 STROBE
int resetPin = 4; // MSGEQ7 RESET
int spectrumValue[7];

// MSGEQ7 OUT pin produces values around 50-80
// when there is no input, so use this value to
// filter out a lot of the chaff.
int filterValue = 80;

// LED pins connected to the PWM pins on the Arduino

int ledPinR = 10;
int ledPinG = 9;
int ledPinB = 11;

void setup()
{
  //Serial.begin(9600);
  // Read from MSGEQ7 OUT
  pinMode(analogPin, INPUT);
  // Write to MSGEQ7 STROBE and RESET
  pinMode(strobePin, OUTPUT);
  pinMode(resetPin, OUTPUT);

  // Set analogPin's reference voltage
//  analogReference(DEFAULT); // 5V

  // Set startup values for pins
  digitalWrite(resetPin, LOW);
  digitalWrite(strobePin, HIGH);
}

void loop()
{
  // Set reset pin low to enable strobe
  digitalWrite(resetPin, HIGH);
  digitalWrite(resetPin, LOW);

  // Get all 7 spectrum values from the MSGEQ7
  for (int i = 0; i < 7; i++)
  {
    digitalWrite(strobePin, LOW);
    delayMicroseconds(30); // Allow output to settle

    spectrumValue[i] = analogRead(analogPin);

    // Constrain any value above 1023 or below filterValue
    spectrumValue[i] = constrain(spectrumValue[i], filterValue, 1023);


    // Remap the value to a number between 0 and 255
    spectrumValue[i] = map(spectrumValue[i], filterValue, 1023, 0, 255);

    // Remove serial stuff after debugging
    //Serial.print(spectrumValue[i]);
    //Serial.print(" ");
    digitalWrite(strobePin, HIGH);
  }

  //Serial.println();  

  // Write the PWM values to the LEDs
  // I find that with three LEDs, these three spectrum values work the best
  analogWrite(ledPinR, spectrumValue[1]);
  analogWrite(ledPinG, spectrumValue[4]);
  analogWrite(ledPinB, spectrumValue[6]);
}

The strips are common anode and the transistors I am using are N-Channel MOSFET 60V 30A : https://www.sparkfun.com/products/10213

The external 12V 5A power supply shares a common ground with the MOSFETs and Arduino. Am I wiring that correctly? I am also using an Arduino Due by the way.

Also, I commented out the line that set the analog reference voltage because I was getting a compiling error. Not sure if that affected anything.

Code: Select all

  // Set analogPin's reference voltage
  //  analogReference(DEFAULT); // 5V

Any thoughts or suggestions? Thanks for your help!