Published June 7, 2021 © GPL3+

Spectrum Analyzer Using MSGEQ7 & 32 x 8 NeoPixel

I made a spectrum analyzer using the MSGEQ7 chip and a 32 x 8 NeoPixel display.

IntermediateShowcase (no instructions)2,213

Spectrum Analyzer Using MSGEQ7 & 32 x 8 NeoPixel

Things used in this project

Hardware components

Breadboard (generic)

MSGEQ7 Breakout Board

32*8 NeoPixel Matrix

Story

youtube link - https://www.youtube.com/watch?v=G8Vz7psLpHA

Main Features:

Uses MSGEQ7’s ability to get 7 frequency bands & displays them across the 32 x 8.

Only uses Adafruit Neopixel Library.

Audio-in can come from any output, and left and right channels are mixed to mono, as to not miss anything.

Detects frequencies from 63Hz-16kHz.

As audio is put in through the 3.5mm jack, the analog output from the MSGEQ7 is sent to the Arduino and set through cases up to 1024, which is the maximum number than can be outputted. The different cases are representative, under void line, of what frequency is being outputted, for example, values of 93-114 represent the 63Hz band.

The multiplexor on the MSGEQ7 switches between digital and analog outputs. The analog output being the frequency out, and the digital being the Strobe pin, which tells the Arduino when to shut off the multiplexor, and the Reset pin, which resets the multiplexor when the Arduino’s reset switch is triggered.

For each of the void LEDs, there are 8 values, each representing the bottom to the top of 32 x 8, as there are 8 LEDs from bottom to top of each level. The LEDoff functions tell when to turn off each LED after each cycle. The reason for 1 & 2 is because after every 8 LEDs, the LEDs snake back the other way (as shown in the previous picture), resulting a long, but condensed, neopixel strip.

There are also the levels 1-7 (sometimes set as 0-6) listed as variable “l” which takes the analog reading and set it under the case values to be shown on the LEDs (0-39). The first set, 0-7, are the first 8 LEDs, but next 8 are listed as 15-8. This is flipped because as previously mentioned, the strip flips after every other column. If the order was normal, the LEDs would turn on upside- down.

Code

Code

#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
#include <avr/power.h>
#endif
#define PIN 7 // neopixels
#define NUMPIXELS 256 
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIN, NEO_GRB + NEO_KHZ800);
int strobePin = 5;  // MSGEQ7 Strobe
int resetPin = 3; // MSGEQ7 Reset
int outPin = A0;  // MSGEQ7 Output 
int level[7]; //7 frequency bands
int l;
uint32_t off =  pixels.Color(255,0,0);
uint32_t red =  pixels.Color(1,1,255);
uint32_t start =  pixels.Color(5,4,0);
uint32_t blue =  pixels.Color(1,0,3);
uint32_t orange =  pixels.Color(210,200,200);


void setup() 
{
  Serial.begin(9600);
  pinMode(strobePin, OUTPUT);
  pinMode(resetPin,  OUTPUT);
  pinMode(outPin, INPUT);
  pinMode(3,OUTPUT);
  digitalWrite(resetPin, LOW);
  digitalWrite(strobePin, LOW);
  delay(1);
  digitalWrite(resetPin, HIGH); // Reseting MSGEQ7 when arduino reset pin is hit
  delay(1);
  digitalWrite(resetPin, LOW);
  digitalWrite(strobePin, HIGH);
  delay(1); 
  
  pixels.begin();
  pixels.show();  // reset pixels
  for (int i = 0; i < 270; i++)
  {
    int ii = i-7; // effect at reset (i found this online and thought it was pretty cool so i included it)
    pixels.setPixelColor(i, start);
    pixels.setPixelColor(ii, blue);
    pixels.show();
    delay(2);
  }
}
void LEDoff1(int a,int b,int c,int d,int e,int f,int g,int h)
{
   for (int i=a; i <=h; i++)
   {                      
    pixels.setPixelColor(i, off);
    pixels.show();
   }
}
void LEDoff2(int a,int b,int c,int d,int e,int f,int g,int h)
{
   for (int i=a; i >=h; i--)
   {                      
    pixels.setPixelColor(i, off);
    pixels.show();
   }
}
void LED0(int a,int b,int c,int d,int e,int f,int g,int h, uint32_t blue)
{
 pixels.setPixelColor(a, orange);
 for (int i=b; i <= h; i++) pixels.setPixelColor(i, off);
}
void LED1(int a,int b,int c,int d,int e,int f,int g,int h)
{
 pixels.setPixelColor(a, orange);    
 pixels.setPixelColor(b, orange);
 for (int i=h; i <= c; i++) pixels.setPixelColor(i, off);
}
void LED2(int a,int b,int c,int d,int e,int f,int g,int h)
{
 pixels.setPixelColor(a, red);
 pixels.setPixelColor(b, orange);
 pixels.setPixelColor(c, orange);
 for (int i=d; i <= h; i++) pixels.setPixelColor(i, off);
}
void LED3(int a,int b,int c,int d,int e,int f,int g,int h)
{
 pixels.setPixelColor(a, red);
 pixels.setPixelColor(b, red);
 pixels.setPixelColor(c, orange);
 pixels.setPixelColor(d, orange);
 for (int i=h; i <= e; i++) pixels.setPixelColor(i, off);
}
void LED4(int a,int b,int c,int d,int e,int f,int g,int h)
{
 pixels.setPixelColor(a, red);
 pixels.setPixelColor(b, red);
 pixels.setPixelColor(c, red);
 pixels.setPixelColor(d, orange);
 pixels.setPixelColor(e, orange);
 for (int i=f; i <= h; i++) pixels.setPixelColor(i, off);
}
void LED5(int a,int b,int c,int d,int e,int f,int g,int h)
{
 pixels.setPixelColor(a, red);
 pixels.setPixelColor(b, red);
 pixels.setPixelColor(c, red);
 pixels.setPixelColor(d, red);
 pixels.setPixelColor(e, orange);
 pixels.setPixelColor(f, orange);
 for (int i=h; i <= g; i++) pixels.setPixelColor(i, off);
}
void LED6(int a,int b,int c,int d,int e,int f,int g,int h)
{
 pixels.setPixelColor(a, red);
 pixels.setPixelColor(b, red);
 pixels.setPixelColor(c, red);
 pixels.setPixelColor(d, red);
 pixels.setPixelColor(e, red);
 pixels.setPixelColor(f, orange);
 pixels.setPixelColor(g, orange);
 for (int i=h; i <= h; i++) pixels.setPixelColor(i, off);
}
void LED7(int a,int b,int c,int d,int e,int f,int g,int h)
{
 pixels.setPixelColor(a, red);
 pixels.setPixelColor(b, red);
 pixels.setPixelColor(c, red);
 pixels.setPixelColor(d, red);
 pixels.setPixelColor(e, red);
 pixels.setPixelColor(f, red);
 pixels.setPixelColor(g, orange);
 pixels.setPixelColor(h, orange);
 for (int i=h; i <=h; i++) pixels.setPixelColor(i, off);
}
void LED8(int a,int b,int c,int d,int e,int f,int g,int h)
{
 pixels.setPixelColor(a, red);
 pixels.setPixelColor(b, red);
 pixels.setPixelColor(c, red);
 pixels.setPixelColor(d, red);
 pixels.setPixelColor(e, red);
 pixels.setPixelColor(f, red);
 pixels.setPixelColor(g, orange);
 pixels.setPixelColor(h, orange);

}
void LED9(int a,int b,int c,int d,int e,int f,int g,int h)
{
 pixels.setPixelColor(a, red);
 pixels.setPixelColor(b, red);
 pixels.setPixelColor(c, red);
 pixels.setPixelColor(d, red);
 pixels.setPixelColor(e, red);
 pixels.setPixelColor(f, red);
 pixels.setPixelColor(g, orange);
 pixels.setPixelColor(h, orange);
}

void line(int a,int b,int c,int d,int e,int f,int g,int h)
{
 switch (l)
 {
  case 93 ... 114:
  LED0(a,b,c,d,e,f,g,h,blue);
  break;
  
  case 115 ... 149:
  LED1(a,b,c,d,e,f,g,h);
  break;
  
  case 150 ... 174:
  LED2(a,b,c,d,e,f,g,h);
  break;
  
  case 175 ... 209:
  LED3(a,b,c,d,e,f,g,h);
  break;
  
  case 210 ... 244:
  LED4(a,b,c,d,e,f,g,h);
  break;
  
  case 245 ... 279:
  LED5(a,b,c,d,e,f,g,h);
  break;
  
  case 280 ... 314:
  LED6(a,b,c,d,e,f,g,h);
  break;
  
  case 315 ... 349:
  LED7(a,b,c,d,e,f,g,h);
  break;
  
  case 350 ... 420:
  LED8(a,b,c,d,e,f,g,h);
  break;
  
  case 421 ... 1024:
  LED9(a,b,c,d,e,f,g,h);
  break;  
 }
}
void loop() 
{
 // Cycle through each frequency band by pulsing the strobe.
 for (int i = 0; i < 7; i++) 
 {
  digitalWrite       (strobePin, LOW);
  delayMicroseconds  (12);   
  level[i] =         analogRead (outPin);
  digitalWrite       (strobePin, HIGH);
  delayMicroseconds  (12);
 }

{
 
 l = level [0];
 line(0,1,2,3,4,5,6,7);
 line(15,14,13,12,11,10,9,8);
 line(16,17,18,19,20,21,22,23);
 line(31,30,29,28,27,26,25,24);
 line(32,33,34,35,36,37,38,39);
 if (l >= 92) LEDoff1(0,1,2,3,4,5,6,7),(15,14,13,12,11,10,9,8),(16,17,18,19,20,21,22,23),(31,30,29,28,27,26,25,24),(32,33,34,35,36,37,38,39);


 l = level [1];
 line(47,46,45,44,43,42,41,40);
 line(48,49,50,51,52,53,54,55);
 line(63,62,61,60,59,58,57,56);
 line(64,65,66,67,68,69,70,71);
 if (l <= 92) LEDoff2(47,46,45,44,43,42,41,40),(48,49,50,51,52,53,54,55),(63,62,61,60,59,58,57,56),(64,65,66,67,68,69,70,71);

 l = level [2];
 line(80,81,82,83,84,85,86,87);
 line(95,94,93,92,91,90,89,88);
 line(96,97,98,99,100,101,102,103);
 line(111,110,109,108,107,106,105,104);
 line(79,78,77,76,75,74,73,72);
 if (l <= 92) LEDoff1(79,78,77,76,75,74,73,72),(80,81,82,83,84,85,86,87),(95,94,93,92,91,90,89,88),(96,97,98,99,100,101,102,103),(111,110,109,108,107,106,105,104);
 
 l = level [3];  
 line(112,113,114,115,116,117,118,119);
 line(127,126,125,124,123,122,121,120);
 line(128,129,130,131,132,133,134,135);
 line(143,142,141,140,139,138,137,136);
 if (l <= 92) LEDoff2(112,113,114,115,116,117,118,119),(127,126,125,124,123,122,121,120),(128,129,130,131,132,133,134,135),(143,142,141,140,139,138,137,136);

 l = level [4];
 line(144,145,146,147,148,149,150,151);
 line(159,158,157,156,155,154,153,152);
 line(160,161,162,163,164,165,166,167);
 line(175,174,173,172,171,170,169,168);
 line(176,177,178,179,180,181,182,183);
 if (l <= 92) LEDoff1(144,145,146,147,148,149,150,151),(159,158,157,156,155,154,153,152),(160,161,162,163,164,165,166,167),(175,174,173,172,171,170,169,168),(176,177,178,179,180,181,182,183);

 l = level [5];
 line(191,190,189,188,187,186,185,184);
 line(192,193,194,195,196,197,198,199);
 line(207,206,205,204,203,202,201,200);
 line(208,209,210,211,212,213,214,215);
 if (l <= 92) LEDoff2(191,190,189,188,187,186,185,184),(192,193,194,195,196,197,198,199),(207,206,205,204,203,202,201,200),(208,209,210,211,212,213,214,215);
 
 l = level [6];            
 line(223,222,221,220,219,218,217,216);
 line(224,225,226,227,228,229,230,231);
 line(239,238,237,236,235,234,233,232);
 line(240,241,242,243,244,245,246,247);
 line(255,254,253,252,251,250,249,248);
 if (l <= 92) LEDoff1(223,222,221,220,219,218,217,216),(224,225,226,227,228,229,230,231),(239,238,237,236,235,234,233,232),(240,241,242,243,244,245,246,247),(255,254,253,252,251,250,249,248);
}
}

Spectrum Analyzer Using MSGEQ7 & 32 x 8 NeoPixel

Things used in this project

Hardware components

Story

Schematics

Diagram from tinkercad

The 7 frequency bands displayed on the 32 x 8

Flowchart

Code

Code

Credits

Anay Patel

Comments

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Spectrum Analyzer Using MSGEQ7 & 32 x 8 NeoPixel

Spectrum Analyzer Using MSGEQ7 & 32 x 8 NeoPixel

Things used in this project

Hardware components

Story

Schematics

Diagram from tinkercad

The 7 frequency bands displayed on the 32 x 8

Flowchart

Code

Code

Credits

Anay Patel

Comments

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