spectrum visualizer not using all assigned LED

Other Hardware LEDs and Multiplexing
1

Hello. Im working on finishing a project I had abandoned some time ago. I'm making a spectrum visualizer using a spark fun MSGEQ7 shield and an Arduino Nano. I'm modifying a sketch I got from who knows where over a year ago. It was originally set up for a 7x20 matrix. 7 columns of 20 ws2812b LEDs. I modified it to work with 7x26 instead. I managed to get them all starting in the correct position but noticed when I try to max out the spectrum it leaves the last 3 LEDs in each column off. I'm not very good at the math of this and figure I have some numbers incorrect in my for loop. I have verified it is not a power delivery issue. Any help is appreciated, I would hate to have wasted some LEDs and leave them unused.

#include <MSGEQ7.h>
 
#include <Adafruit_NeoPixel.h>
//#define A0
//#define A1
#define pinReset 5
#define pinStrobe 4
#define BRIGHTNESS 50
 
#define LEDs 182 //total number of LEDs
#define PIN 12
#define BUTTON_PIN 10
 
#define OffColor 0x000000    // OFF
int SpectrumLeft[7];
int SpectrumRight[7];


//int red_rainbow3[26] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
//int green_rainbow3[26] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
//int blue_rainbow3[26] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

 
int red[26];
int green[26];
int blue[26];
 
int red_rainbow[26] = {91,255,127,0,0,0,0,0,0,0,0,0,64,127,191,255,255,255,255,189,189,189,189,0,0,64};
int green_rainbow[26] = {2,0,0,0,64,127,191,255,255,255,255,255,255,255,255,255,191,0,0,0,0,0,0,0,0,255};
int blue_rainbow[26] = {47,255,255,255,255,255,255,255,191,127,64,0,0,0,0,0,0,0,0,0,0,0,0,0,0,75};

int red_rainbow2[26] = {255,255,200,200,185,185,170,170,155,155,120,120,110,110,110,98,98,92,92,85,85,45,40,0,0,0};
int green_rainbow2[26] = {0,0,0,7,9,12,14,17,19,22,26,30,37,40,45,47,50,55,59,63,69,72,78,82,90,100};
int blue_rainbow2[26] = {20,10,8,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,70,85,100,115};

int red_spect[26] = {15,25,32,45,53,60,68,75,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
int green_spect[26] = {0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
int blue_spect[26] = {255,255,255,225,225,220,210,200,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

 
int j;

int SpectrumGraphLeft[7][26];
int SpectrumGraphRight[7][26];
 
Adafruit_NeoPixel Strip = Adafruit_NeoPixel(LEDs, PIN, NEO_GRB + NEO_KHZ800);
 
//#define MSGEQ7_INTERVAL ReadsPerSecond(50)
//#define MSGEQ7_SMOOTH 191 // Range: 0-255
 
//CMSGEQ7<MSGEQ7_SMOOTH, pinReset, pinStrobe, pinAnalogleft> MSGEQ7;
 
// Choose a PWM pin!
#define pinLed 22
 
bool oldState = HIGH;
int showType = 0;
 
void setup()
{
 
Serial.begin(9600);
Strip.setBrightness(BRIGHTNESS);
 
 
//pinMode(pinAnalogleft, INPUT);
pinMode(pinStrobe, OUTPUT);
pinMode(pinReset, OUTPUT);
//analogReference(DEFAULT);
 
digitalWrite(pinStrobe,LOW);
digitalWrite(pinReset,HIGH);
digitalWrite(pinStrobe,HIGH);
digitalWrite(pinStrobe,LOW);  //Strobe pin on the shield (go to next Band)
digitalWrite(pinReset,LOW);
 
// Assign pixels to graph array
  for (byte bar = 0 ; bar < 7 ; bar++)
 
  {
                if ( bar == 0)             
                {
    for (byte pixel = 0 ; pixel < 26 ; pixel ++)
              
    {
      SpectrumGraphLeft[bar][pixel] = (bar * 26) + pixel;  //first
      SpectrumGraphRight[bar][pixel] = (-1*pixel)+268;
    }    // end for
                }
                else if ( bar == 1) //flipped strip
                {
                for (byte pixel = 0 ; pixel < 26  ; pixel ++)
    {
      SpectrumGraphLeft[bar][pixel] = (-1*pixel)+51;   //second
      SpectrumGraphRight[bar][pixel] = (pixel)+252;
    }    // end for
                }
                 else if (bar ==2)
                {
                for (byte pixel = 0 ; pixel < 26 ; pixel ++)
    {
      SpectrumGraphLeft[bar][pixel] = ((bar) * 26) + pixel;     //third
      SpectrumGraphRight[bar][pixel] = (-1*pixel)+252;
     
    }    // end for
     }
                 else if (bar == 3) //flipped strip
                {
                 for (byte pixel = 0 ; pixel < 26  ; pixel ++)
    {
      SpectrumGraphLeft[bar][pixel] = (-1*pixel)+103;   //fourth
      SpectrumGraphRight[bar][pixel] = (pixel)+224;
    }    // end for
                }
                else if (bar == 4)
                {
                  for (byte pixel = 0 ; pixel < 26  ; pixel ++)
    {
      
      SpectrumGraphLeft[bar][pixel] = ((bar) * 26) + pixel;      //fifth
      SpectrumGraphRight[bar][pixel] = (-1*pixel)+212;  
        }    // end for         
                }
 
                else if  (bar == 5)
                {
                  for (byte pixel = 0 ; pixel < 26  ; pixel ++)
    {
      SpectrumGraphLeft[bar][pixel] = (-1*pixel)+155;     //sixth
      SpectrumGraphRight[bar][pixel] = (pixel)+197;   
        }    // end for         
                }
                else if  (bar == 6)
                {
                  for (byte pixel = 0 ; pixel < 26  ; pixel ++)
    {
      SpectrumGraphLeft[bar][pixel] = ((bar) * 26) + pixel;     //seventh
      SpectrumGraphRight[bar][pixel] = (-1*pixel)+261;   
        }    // end for         
                }   
  } // end for
 
pinMode(BUTTON_PIN, INPUT_PULLUP); 
Strip.begin();
Strip.show(); // Initialize all pixels to 'off'
 
}

void startShow(int i) {
  switch(i){
   
    case 1: // Rainbow
  for (j=0; j<26; j++)
    {
    red[j] = red_spect[j];
    green[j] = green_spect[j];
    blue[j] = blue_spect[j];
    }
   mapSpectrum();
            break;
    
    
    case 2:  //Red
    for (j=0; j<26; j++)
    {
    red[j] = red_rainbow2[j];
    green[j] = green_rainbow2[j];
    blue[j] = blue_rainbow2[j];
    }
    mapSpectrum();   
            break;
           
  case 3:  //Blue
    for (j=0; j<26; j++)
    {
    red[j] = 0;
    green[j] = 0;
    blue[j] = 225;
    }
    mapSpectrum();   
            break;
           
       
    case 4:  //Green
    for (j=0; j<26; j++)
    {
    red[j] = 0;
    green[j] = 255;
    blue[j] = 0;
    }
    mapSpectrum();   
            break; 




            
}
} 
 
void loop()
{
 
  Serial.print(SpectrumGraphLeft[7][26]);
  Serial.print(SpectrumGraphRight[7][26]);
  readSpectrum();      // Get values from spectrum shield
  mapSpectrum();      // Color pixels according to spectrum values   
  
   
 // delay(15);
 
  // Get current button state.
  bool newState = digitalRead(BUTTON_PIN);
 
  // Check if state changed from high to low (button press).
  if (newState == LOW && oldState == HIGH) {
    // Short delay to debounce button.
    delay(20);
    // Check if button is still low after debounce.
    newState = digitalRead(BUTTON_PIN);
    if (newState == LOW) {
      showType++;
      if (showType > 4)
        showType=1;
      startShow(showType);
    }
   
  }
// Set the last button state to the old state.
  oldState = newState;
 
}
 

void readSpectrum()
{
  // Band 0 = Lowest Frequencies.
  byte Band;
  for(Band=0;Band <7; Band++)
  {
    SpectrumLeft[Band] = analogRead(A0); //left
    SpectrumRight[Band] = analogRead(A1); //right
   
    digitalWrite(pinStrobe,HIGH);
    digitalWrite(pinStrobe,LOW);
    //delayMicroseconds(50);
 
      }
   
    
}
 
 
 
 

 
 
void mapSpectrum()    // map spectrum to pixel strips
{
  for(byte Band=0 ; Band <7 ; Band++)
  {    
    SpectrumLeft[Band] = map(SpectrumLeft[Band],100 , 800, 0, 19);
    SpectrumRight[Band] = map(SpectrumRight[Band], 45, 800, 0, 19);
  
  for(int Pixel = 0; Pixel < SpectrumLeft[Band]; Pixel++){
    Strip.setPixelColor(SpectrumGraphLeft[Band][Pixel], red[Pixel],green[Pixel],blue[Pixel]);
}
                for (byte Pixel = SpectrumLeft[Band] ; Pixel < 26 ; Pixel++)
                                {      // Turn the rest OFF!
                                               Strip.setPixelColor(SpectrumGraphLeft[Band][Pixel], OffColor);
                                }    // end for (Pixel
 
   for(int Pixel = 0; Pixel < SpectrumRight[Band]; Pixel++){
    Strip.setPixelColor(SpectrumGraphRight[Band][Pixel], red[Pixel],green[Pixel],blue[Pixel]);
}
                for (byte Pixel = SpectrumRight[Band] ; Pixel < 26 ; Pixel++)
                                {      // Turn the rest OFF!
                                               Strip.setPixelColor(SpectrumGraphRight[Band][Pixel], OffColor);
                                }    // end for (Pixel
                          
 
  }    // end for (Band

  Strip.show();
   
 
 
 
}
2

This sounds like a hardware problem but that is a guess. The first thing I would suggest is getting the schematic, not a frizzy thing, and posting it. Be sure it is what you build, not what you thought you built. Be sure to show all power and ground connections.

3

I don't suspect it's a hardware failure. It works as designed except for the last of the LEDs in each column not lighting. I have tested the wiring. The sparkfun shield only provides an input to the arduinio and is working as it should. The Nano is wired properly and I get the desired effect I want besides the last few LEDs not lighting. But I could be wrong of course. I'll try and get a schematic together tonight.

There are other colors triggered by a push button. Once it's powered on the LEDs default to off. First buttons press shows a custom color scheme of which the last 3 LEDs do not illuminate. The other 3 settings are solid colors (red, blue and green) they are only missing 2 LEDs.

4

Well I am very happy to say that I actually figured this out all on my own. I studied the code and learned what each part did (more or less) and ended up learning about the map function.

This bit of code is what was messing me up. map(value, fromLow, fromHigh, toLow, toHigh)
I figured out that the last value was where it was telling the strip to end. I changed it from 19 to 25. It clicked after reading about the map function that the original value was set to 19 because its 0 indexed for the original set up witch used 20 LEDs per row. Thanks to some patience and the info available in the reference catalog on this website I was able to learn how to get this working properly. Well this portion anyways, there are other bugs to work out yet.

void mapSpectrum()    // map spectrum to pixel strips
{
  for(byte Band=0 ; Band <7 ; Band++)
  {    
    SpectrumLeft[Band] = map(SpectrumLeft[Band],100 , 800, 0, 25);
    SpectrumRight[Band] = map(SpectrumRight[Band], 45, 800, 0, 25);
5

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