Custom mapped matrix

[mattncsu]

I attempted to define a matrix across a neopixel 4 digit 7-segment display I made and then made a demo to basically scroll a horizontal then vertical line across the matrix as a test. It sort of works in that I see pixels lighting up left to right then top to bottom but they aren't in a perfect line. Am I doing anything obvious wrong? I triple checked my remap function and didn't see any errors.

Here is a video showing my PCB and what I'm seeing: https://imgur.com/a/d6oy3uL

The code that produces that is below, any thought on what might be happening?

#include <Adafruit_GFX.h>
#include <FastLED_NeoMatrix.h>
#include <FastLED.h>

#define PIN 18
#define BRIGHTNESS 10

#define mw 25
#define mh 9
#define NUMMATRIX (mw*mh)
CRGB leds[NUMMATRIX];
// Define matrix width and height.
FastLED_NeoMatrix *matrix = new FastLED_NeoMatrix(leds, mw, mh, 
  NEO_MATRIX_TOP     + NEO_MATRIX_LEFT +
    NEO_MATRIX_ROWS + NEO_MATRIX_PROGRESSIVE);

// This could also be defined as matrix->color(255,0,0) but those defines
// are meant to work for adafruit_gfx backends that are lacking color()
#define LED_BLACK    0

#define LED_RED_VERYLOW   (3 <<  11)
#define LED_RED_LOW     (7 <<  11)
#define LED_RED_MEDIUM    (15 << 11)
#define LED_RED_HIGH    (31 << 11)

#define LED_GREEN_VERYLOW (1 <<  5)   
#define LED_GREEN_LOW     (15 << 5)  
#define LED_GREEN_MEDIUM  (31 << 5)  
#define LED_GREEN_HIGH    (63 << 5)  

//    .0 .1 .2 .3 .4 .5 .6 .7 .8 .9 10 11.12 13 14 15 16 17 18 19 20 21 22 23 24
// 0  .. .1 .2 .3 .. .. .. 22 23 24 .. .. .. .. .. 43 44 45 .. .. .. 64 65 66 ..
// 1  18 .. .. .. .4 .. 39 .. .. .. 25 .. .. .. 60 .. .. .. 46 .. 81 .. .. .. 67
// 2  17 .. .. .. .5 .. 38 .. .. .. 26 .. 85 .. 59 .. .. .. 47 .. 80 .. .. .. 68
// 3  16 .. .. .. .6 .. 37 .. .. .. 27 .. .. .. 58 .. .. .. 48 .. 79 .. .. .. 69
// 4  .. 19 20 21 .. .. .. 40 41 42 .. .. .. .. .. 61 62 63 .. .. .. 82 83 84 ..
// 5  15 .. .. .. .7 .. 36 .. .. .. 28 .. .. .. 57 .. .. .. 49 .. 78 .. .. .. 70
// 6  14 .. .. .. .8 .. 35 .. .. .. 29 .. 86 .. 56 .. .. .. 50 .. 77 .. .. .. 71
// 7  13 .. .. .. .9 .. 34 .. .. .. 30 .. .. .. 55 .. .. .. 51 .. 76 .. .. .. 72
// 8  .. 12 11 10 .. .. .. 33 32 31 .. .. .. .. .. 54 53 52 .. .. .. 75 74 73 ..


uint16_t myRemapFn(uint16_t x, uint16_t y) {
    switch(y){
    case 0:
      switch(x){
          case 1: return 1;
          case 2: return 2;
          case 3: return 3;
          case 7: return 22;
          case 8: return 23;
          case 9: return 24;
          case 15: return 43;
          case 16: return 44;
          case 17: return 45;
          case 21: return 64;
          case 22: return 65;
          case 23: return 66;
          default: return 87;
      }
    
    case 1:
      switch(x){
        case 0: return 18;
        case 4: return 4;
        case 6: return 39;
        case 10: return 25;
        case 14: return 60;
        case 18: return 46;
        case 20: return 81;
        case 24: return 67;
        default: return 87;
      }
    case 2:
      switch(x){
        case 0: return 17;
        case 4: return 5;
        case 6: return 38;
        case 10: return 26;
        case 12: return 85;
        case 14: return 59;
        case 18: return 47;
        case 20: return 80;
        case 24: return 68;
        default: return 87;
      }   
    case 3:
      switch(x){
        case 0: return 16;
        case 4: return 6;
        case 6: return 37;
        case 10: return 27;
        case 14: return 58;
        case 18: return 48;
        case 20: return 79;
        case 24: return 69;
        default: return 87;
      }   
    case 4:
      switch(x){
          case 1: return 19;
          case 2: return 20;
          case 3: return 21;
          case 7: return 40;
          case 8: return 41;
          case 9: return 42;
          case 15: return 61;
          case 16: return 62;
          case 17: return 63;
          case 21: return 82;
          case 22: return 83;
          case 23: return 84;
          default: return 87;
      }   
    case 5:
      switch(x){
        case 0: return 15;
        case 4: return 7;
        case 6: return 36;
        case 10: return 28;
        case 14: return 57;
        case 18: return 49;
        case 20: return 78;
        case 24: return 70;
        default: return 87;
      }   
    case 6:
      switch(x){
        case 0: return 14;
        case 4: return 8;
        case 6: return 35;
        case 10: return 29;
        case 12: return 86;
        case 14: return 56;
        case 18: return 50;
        case 20: return 77;
        case 24: return 71;
        default: return 87;
      }   
    case 7:
      switch(x){
        case 0: return 13;
        case 4: return 9;
        case 6: return 34;
        case 10: return 30;
        case 14: return 55;
        case 18: return 51;
        case 20: return 76;
        case 24: return 72;
        default: return 87;
      }   
    case 8:
      switch(x){
          case 1: return 12;
          case 2: return 11;
          case 3: return 10;
          case 7: return 33;
          case 8: return 32;
          case 9: return 31;
          case 15: return 54;
          case 16: return 53;
          case 17: return 52;
          case 21: return 75;
          case 22: return 74;
          case 23: return 73;
          default: return 87;
      }   
  } 
}

void scrolling_line(){
 
  for (uint8_t i = 0;i<mw;i++){
    matrix->clear();
    matrix->drawLine(i,0,i,mh,LED_RED_HIGH);
    matrix->show();
    delay(500);
  }
  for (uint8_t i = 0;i<mh;i++){
    matrix->clear();
    matrix->drawLine(0,i,mw,i,LED_GREEN_HIGH);
    matrix->show();
    delay(500);
  }
}

void setup() {
  // put your setup code here, to run once:
// Time for serial port to work?
    delay(1000);
    Serial.begin(115200);
    Serial.print("Init on pin: ");
    Serial.println(PIN);
    Serial.print("Matrix Size: ");
    Serial.print(mw);
    Serial.print(" ");
    Serial.print(mh);
    Serial.print(" ");
    Serial.println(NUMMATRIX);
    FastLED.addLeds<NEOPIXEL,PIN>(  leds, NUMMATRIX  ).setCorrection(TypicalLEDStrip);
    Serial.print("Setup serial: ");
    Serial.println(NUMMATRIX);
    matrix->begin();
    matrix->setTextWrap(false);
    matrix->setBrightness(BRIGHTNESS);
    matrix->setRemapFunction(myRemapFn);
}

void loop() {
  // put your main code here, to run repeatedly:
scrolling_line();
}

[marcmerlin]

Ok, this is an "interesting" application.
I'll be honest that I don't really have time to help with 1-1 support of other people's projects, and I've actually never had to use the custom remap function (which I inherited from Adafruit::NeoMatrix), although it should still work since what it's doing is reasonably simple.

Back to your application, I don't even know how your neopixels are wired, so it's kind of hard for me to provide a quick suggestion. I see your comment, I just can't verify it's wired right :)
One thing that jumps to mind is that your first pixel is '0', not '1', so you're going to be offset by one.
Not sure if that's enough to mess up the display just like yo show on the video, but it's possible.
I'll close this since I'm pretty certain there is no issue with the library function itself. Hopefully the off by 1 is enough to solve your problem.

[mattncsu]

That's probably it, thanks for looking at it. I'll try it out tonight.

[mattncsu]

Just following up to confirm that starting the led string at 0 fixed it. Thanks again!

[marcmerlin]

haha, cool. So I guess you triple checked but were only off by one :)

[mattncsu]

Well.... I tripple checked it without remembering the strip numbering started at zero (despite doing it correctly in a different sketch) 🤔

[marcmerlin]

I added this to the documentation, thanks again for the example: https://github.com/marcmerlin/Framebuffer_GFX/blob/master/README.md#custom-xy-mapping-for-irregular-arrays

[ImanCol]

Can you help me create a Custom Mappings for this project?
They are 592 LEDs ws2812b. I'll use an ESP32 (Test Arduino)

VID-20210727-WA0008.mp4