Hey Gang, the shield I recently received had the Reset pin on D5, not D6.

Hi, can I use this shield with an Arduino MEGA?

I'm working on a project to connect a metal detector to an Arduino and analyse the amplitude/frequency of the input sound for automated metal detection on a robot.

The data sheet wires the left and right channel from the audio into the msgeq7 with 2 22k resistors for each channel into the .01uF(10nF) capacitor then into the Audio In pin but I’ve seen other people (like this shield) hook it up with only the capacitor, either 10nF or 1nF. what is the difference between using the 22k resistors+capacitor vs the capacitor only? and also is there a benefit when it comes to output readings when using 1 msgeq7 for mono or using 2 msgeq7’s for stereo reading left and right independently? thank you to anyone who responds :)

This has been on backorder for sometime. Is it being replaced? Any thoughts on an update that auto filters noise? In canada my usual sources say they no longer sell this.

I want to use this to connect between speaker and amp instead of line in. Thanks to someone's code, I got a basic vu meter going on line in, then I put the contraption between speaker and amp. After adding a few hundred ohms of resistance, I had a amp monitor that worked well. I figure the impedance is so high this thing won't get hurt, but am I missing something? Seems too easy.

Would I be able to use this board hooked up to an external mic board that's sampling music instead of using the stereo Jacks?

I have this :Electret Microphone Amplifier - MAX9814 with Auto Gain Control https://www.adafruit.com/products/1713 Thank You

Another poor buy, I had bought this board last year before the took them off the site to fix a problem with the old board. When this model came back online I was very excited to be able to build with it again. The only problem is once I bought it and set up my circuit, it only worked properly for about an hour. After this it began to have a heavy noise interference and not work properly. Very disappointed.

For anyone looking for a place to start, I made a compact class for the shield (very bare bones, but it makes the application code look really nice). Copy the code below labelled "Header File" into a file called "Sparkfun_Spectrum_Shield.h" and the code labelled "CPP File" into a file called "Sparkfun_Spectrum_Shield.cpp" and put both of those into your Arduino project folder.

Header File:

#ifndef SPARKFUN_SPECTRUM_SHIELD_H
#define SPARKFUN_SPECTRUM_SHIELD_H

#include <Arduino.h>

class Sparkfun_Spectrum_Shield
{
private:
    int reset_pin_;
    int strobe_pin_;
    int right_pin_;
    int left_pin_;

public:
    // The following arrays hold the analog values for the 7 bands
    // and are updated when the .Update() function is called
    int right_channel[7];
    int left_channel[7];
    int average[7];

    void Init();
    void Update();

    Sparkfun_Spectrum_Shield(); //Constructor that uses pins defined by
                                //how the shield if physically laid out
    Sparkfun_Spectrum_Shield(int reset,int strobe,int right,int left);
};

#endif

CPP File:

#include "Sparkfun_Spectrum_Shield.h"

Sparkfun_Spectrum_Shield::Sparkfun_Spectrum_Shield()
{
    reset_pin_ = 5;
    strobe_pin_ = 4;
    right_pin_ = 1;
    left_pin_ = 0;
}

Sparkfun_Spectrum_Shield::Sparkfun_Spectrum_Shield(int reset,int strobe,int right,int left)
{
    reset_pin_ = reset;
    strobe_pin_ = strobe;
    right_pin_ = right;
    left_pin_ = left;
}

void Sparkfun_Spectrum_Shield::Init()
{

    //Initialize pins for spectrum analyzer
    pinMode(reset_pin_, OUTPUT);
    pinMode(strobe_pin_, OUTPUT);
    digitalWrite(strobe_pin_, HIGH);
    digitalWrite(reset_pin_, HIGH);

    //Initialize spectrum analyzer
    digitalWrite(strobe_pin_, LOW);
    delay(1);
    digitalWrite(reset_pin_, HIGH);
    delay(1);
    digitalWrite(strobe_pin_, HIGH);
    delay(1);
    digitalWrite(strobe_pin_, LOW);
    delay(1);
    digitalWrite(reset_pin_, LOW);
    delay(5);
}

void Sparkfun_Spectrum_Shield::Update()
{
    // Band 0=63Hz, 1=160Hz, 2=400Hz, 3=1kHz, 4=2.5kHz, 5=6.25kHz, 6=16kHz
    byte band;

    for (band = 0; band < 7; band++)
    {
        //Read twice and take the average by dividing by 2
        right_channel[band] = (analogRead(left_pin_) + analogRead(left_pin_) ) >> 1;
        //Read twice and take the average by dividing by 2
        left_channel[band] = (analogRead(right_pin_) + analogRead(right_pin_) ) >> 1;

        //Compute average of left and right channel
        average[band] = (right_channel[band]+left_channel[band])/2;

        //Strobe to get next frequency bin
        digitalWrite(strobe_pin_, HIGH);
        digitalWrite(strobe_pin_, LOW);
    }
}

Example Main .ino File:

#include "Sparkfun_Spectrum_Shield.h"

Sparkfun_Spectrum_Shield spectrum = Sparkfun_Spectrum_Shield();

void setup()
{
    //initialize spectrum shield
    spectrum.Init();

    //open serial terminal connection
    Serial.begin(9600);
}

void loop()
{
    spectrum.Update();

    for (int i = 0; i < 7; i++)
    {
        Serial.println(spectrum.average[i]);
    }

    delay(100);
}

I wish I could return it. Reset pin on 5 instead of 6 so if you are trying to follow examples, good luck. Ridiculously noisy. Don't buy this thing. Not worth $10, much less $30.

This shield puts the FUN in SparkFun! (Sorry)

Wanted to share code for newbs like myself who found the examples didn't work quite like I was expecting. This code uses the same board / LED configuration as SF example, but produces more of a peak level meter.

A good tip from the linked github repository points out that the A0 and A1 pins are reading left and right channels. The code grabs all 7 frequencies from both channels, adds them up, and lights more LEDs the higher the number.

One code mod to try is lighting all LEDs just on the highest sum which will typically cause the lights to strobe to the beat. You may need to adjust thisSum ranges according to your card / audio source.

/************************************************
This sketch acts like the old peak level indicators
on stereo equipment. 
*************************************************/

//Declare Spectrum Shield pin connections
#define STROBE 4
#define RESET 6
#define DC_One A0
#define DC_Two A1

int Spectrum[7];
int thisSum;
byte Band;

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

  //Set LED pin configurations
  pinMode(7, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);

  //Set spectrum Shield pin configurations
  pinMode(STROBE, OUTPUT);
  pinMode(RESET, OUTPUT);
  pinMode(DC_One, INPUT);
  pinMode(DC_Two, INPUT);  
  digitalWrite(STROBE, HIGH);
  digitalWrite(RESET, HIGH);

  //Initialize Spectrum Analyzers
  digitalWrite(STROBE, LOW);
  delay(1);
  digitalWrite(RESET, HIGH);
  delay(1);
  digitalWrite(STROBE, HIGH);
  delay(1);
  digitalWrite(STROBE, LOW);
  delay(1);
  digitalWrite(RESET, LOW);
}

void loop() {
  thisSum = 0;

  // Read in all 7 channels into array
  for(Band=0;Band <7; Band++)
  {
    Spectrum[Band] = (analogRead(0) + analogRead(1) ) >>1; //Read left then right channels then average by dividing by 2
    digitalWrite(STROBE,HIGH);
    digitalWrite(STROBE,LOW);
  }
  // Add up the sum of the output
  for(Band=0;Band <7; Band++) {
    thisSum += Spectrum[Band];
  }
  // Light LEDs according to sum
  // Noise level seems to hover just under 550
  if (thisSum > 550) { digitalWrite(7, HIGH); } else { digitalWrite(7, LOW); }
  if (thisSum > 600) { digitalWrite(8, HIGH); } else { digitalWrite(8, LOW); }
  if (thisSum > 700) { digitalWrite(9, HIGH); } else { digitalWrite(9, LOW); }
  if (thisSum > 800) { digitalWrite(10, HIGH); } else { digitalWrite(10, LOW); }
  if (thisSum > 900) { digitalWrite(11, HIGH); } else { digitalWrite(11, LOW); }
  if (thisSum > 1000) { digitalWrite(12, HIGH); } else { digitalWrite(12, LOW); }
  if (thisSum > 1100) { digitalWrite(13, HIGH); } else { digitalWrite(13, LOW); }
}

Is there any reason why you chose pin 4 & 6? I dont see any real logic for this decision. Just asking because I am coding an MSGEQ7 Lib with examples. And those examples should work with the shield as well. Was there any intention behind this?

Just thought I'd share this: On my shield, Pin 6 is not connected to anything at all! Reset goes to Pin 5, I repeat Pin 5!! It has taken me a year to realise this and explains why I haven't been able to make it run through less than the seven bands. I've checked the board thoroughly and I'm afraid, Sparkfun, it's not me that's mad. Just wondering how this passed your testing? So countless people out there are carefully timing the reset when there is nothing connected to it - how mad is that?

Is there any update on when this will be back in stock?

I've been working with this version of the spectrum shield for a few weeks now and I've noticed something. Both equalizers return values on each of the bands when there is no input ( < 100 ). This happens both when there is no audible signal coming over the input line and when there's nothing plugged in to the input line at all.

Is this an expected behavior?

Got mine a week ago but having problems audio out - the audio doesn't sound right when it pass through the shield. Tried different 4 male to male audio cables (cables them self work fine), different audio source and headphones/speaker. Also tried it with power on and off. seems like something wrong with the shield I got :(

Nice to see that this product lives on (=gets updated). :-)

I still don't understand why you have two jacks for "passthrough" when a simple 3.5 mm stereo splitter is a rather cheap and flexible solution. It would possibly make sense if you had some sort of "jumper" so that you could separate them and one as input and the other as modified/filtered output based on your own MSGEQ7 code but as far as I can see there are just straight traces between the two jacks.

IMHO a compact MSEQ7 breakout board would probably be more convenient in several cases (compact speaker builds etc).

It would be very convenient to either have a small board with the necessary MCU pins in one end, audio "LGR" pins in the other end and two MSEQ7 chips with checked/"tuned" support components in the middle OR a similar compact board with a single 3.5 mm jack in the "audio" end and all 8 pins (VCC, GND, Reset, Strobe, AnalogOutL, AnalogOutR, AudioInL ,AudioInR) on the other end.

That way you could use it as a slightly longer but much smarter version of the 3.5 mm jack breakout board.

hello, I am working on a project using the spectrum shield to have leds react to music. The sprectrum shield has an input and an output, one for the speaker and one for the stereo input from phone. Question is I want to use a Bluetooth speaker so we can send the music wirelessly through phone, will it work like that? so the input jack wont have an input

When do you expect these back in stock?

Looking at the schematic, C1 and C3 are given as 1,000pF. When I look at the data sheet (http://www.mix-sig.com/images/datasheets/MSGEQ7.pdf) the values are given as 0.1uF (100,000pF). It seems like this deviation may mean some of the sharper volume peaks are missed? I could be wrong ...

I see you're using the SMD version of the MSGEQ7. Will you be selling them?

Has anything changed from the previous version besides the header layout?