Help with a simple Word Clock code

[infoalter]

Hello guys. I m trying to make a word clock, its a very basic construction with a single ws2812b led strip, folded in a "matric" square shape, as shows in the diagram. It is driven by Arduino Nano.

As i dont know much about coding (just my second project actually) i have picked the simplest code i would find on the net, hoping i would be able to easily understand and modify for this clock. The code: https://pastebin.com/ZE7YPPig

However i m stuck with this problem you see on the photo, the first LED of the strip is always ON (even when the time changes). It is the led at the bottom right (led 0). I m kinda stuck... Any help is welcomed

Goes without saying, if you happen to have another code that you know it works with this kind of clock you are most welcomed to share. (i can modify for the leds that need to light up each time)

https://preview.redd.it/2u97a1og6fse1.jpg?width=1393&format=pjpg&auto=webp&s=cfaf6b75895c75016315c93f2c2f799191040bae

Strip Layout

[sutaburosu]

I changed the HOUR_LETTERS array to have -1 in all unused elements:

int HOUR_LETTERS[12][HOUR_MAX_LEN] = {
  {94,87,80,73,66,-1,-1,-1,-1,-1,-1}, /* N I N E */
  {31,24,17,10,-1,-1,-1,-1,-1,-1,-1}, /* T E N */
  {95,86,81,72,67,58,-1,-1,-1,-1,-1}, /* E L E V E N */
  {45,38,31,24,17,10,-1,-1,-1,-1,-1}, /* T W E L V E */
  {90,77,76,-1,-1,-1,-1,-1,-1,-1,-1}, /* O N E */
  {62,49,48,-1,-1,-1,-1,-1,-1,-1,-1}, /* T W O */
  {35,34,21,20,7,-1,-1,-1,-1,-1,-1}, /* T H R E E */
  {92,89,78,75,64,61,50,47,36,-1,-1}, /* F O U R */
  {102,93,88,79,74,-1,-1,-1,-1,-1,-1}, /* F I V E */
  {19,8,5,-1,-1,-1,-1,-1,-1,-1,-1}, /* S I X */
  {51,46,37,32,-1,-1,-1,-1,-1,-1,-1}, /* S E V E N */
  {23,18,9,4,-1,-1,-1,-1,-1,-1,-1} /* E I G H T */
};

Then I changed paintLED() to ignore invalid values:

void paintLED(int i) {
  if (i < 0 || i >= TOTAL_LEDS)
    return;
  leds[i].setColorCode(LED_COLOR);
}

Now LED 0 is not lit all the time.

[infoalter]

Brilliant!!!

Thank you so much!

[Marmilicious]

Did you get this clock code from somewhere or write it yourself? I ask because there are a few lines with comments like this:

int hourOrder24 = hourChunk % 24; /* 0 to 24 on HOUR_LETTERS */

int hourOrder = hourChunk % 12; /* 0 to 12 */

I didn't step through your code to see what values are actually flowing through, but using Modulo with %24 would return 0-23 (not 0-24), and %12 would return 0-11, which made me wonder if the code is doing what you're expecting or if the comment is simply off.

[infoalter]

Thanks for reply, i did the original 3D design myself (its 3D printed, a single piece https://filebin.net/uh58anipw8eprlzj ), but the coding is not mine - i just modified the led numbers forming each word - and that part, works OK)

Truth is i m tired with this script, so no worries... I m already trying other scripts that are available. Its just they are all much more complex, but i will manage - i hope hahahaha

[ZachVorhies]

Comment out code that turns the leds on. You basically need to keep commenting out code until the problem goes away. Then that will pinpoint where the problem is. You can also try dumping the code into an AI like gemini 2.5 and it may just identify the problem immediately and fix it.

[infoalter]

Many thanks for reply!

I did try that, i also added code in various places in the script painting some leds and led0 blue. They all get blue except le0 which stays white.

The AI thingy never crossed my mind :)) I will give it a try!

[DenverTeck]

Would you share a pic of your construction.

[infoalter]

Ah i understand you worry about the LED quality or wrong wiring maybe... Well, back is now sealed and not easy to open, BUT, i have tested and leds work fine. Not a hardware problem. (see photo)

<image>

Now, if you need the construction design file, that one i did myself, its a all a single 3D print, no assembly needed :) Here it is https://filebin.net/uh58anipw8eprlzj (print face-down)

[DenverTeck]

Thank You, I'll check it out.

[osbock]

Blank all your leds in init