Using SmartMatrix library with HUB12 monochrome panels

[Abacus]

Hi all!
I’m using ESP32 and P10 HUB12 panel. I want to use SmartMatrix library for my project.

I already connected everything to my ESP32 board and using multi row refreshing mapping example i got something shown.
I’m using only A and B pins so look’s like when example code goes to height above 2 nothing is shown.

So before going to deep by my own i would like to ask some help figuring how to use this library with this type of panels.

Thanks.

https://youtu.be/DXFlJaDSEjQ

[marcmerlin]

I don’t think SmartMatrix supports AB panels, so you’d have to write your own mapping function

[Louis]

Can you share a picture of the back of your panel? Do you have a link to where you bought the panel?

[Abacus]

[Abacus]

Sorry but I don’t have a link because I just bought it in local store.

[Louis]

It’s a HUB12 (not HUB75) pinout. You can search Google Images for what a HUB12 pinout looks like.

I added limited support for HUB12 panels, with some brief info here:

SmartMatrix with 1/4 scan hub75 panels

Thanks to a generous donation from Martin Welford (@viking), I’m happy to say that the teensylc branch now has support for panels with non-linear pixel mapping, including multi-row-mapping, like the 1/4 scan panels mentioned above. I added this support to both the ESP32 and Teensy on that branch. Adding support for new panels requires some code changes, but it’s mostly copy/paste and modifying numbers, not actual coding from scratch, so it’s accessible to more people. There’s documentation in…

Some more details are in the ESP32 branch README:

pixelmatix/SmartMatrix

[Abacus]

Great. Thanks a lot for your help. Works fine but there some ghost effect around numbers. How I can fix this?

[Louis]

I’m not exactly sure what’s going on here, but it looks like some kind of issue with clock timing or polarity.

I may have broken something on the ESP32 branch with this commit, can you reverse this commit locally and see if it works better?

invert I2S CLK output to clock out data on rising edge

[Abacus]

Sorry for late response. After i revert commit suggested above whole screen just lit and nothing works. i revert it back and it still inverted.

I slightly change example code. Just inverted colors.

void loop() {
  for(int j=0; j<kMatrixHeight; j++) {
    rgb24 colorByHeight;
    colorByHeight.red = 0;
    if(j & 0x01)
      colorByHeight.green = 0xff;
    if(j & 0x02)
      colorByHeight.blue = 0xff;
      
    for(int i=0; i<kMatrixWidth; i++) {
      backgroundLayer.drawPixel(i,j,colorByHeight);
      backgroundLayer.swapBuffers();   
      delay(250);  

      backgroundLayer.fillScreen({0xff,0xff,0xff});
    }
  }
}

Then i decrease brightness to 5.

I’m not sure how signals should look like but seems like something is wrong hire.

[Louis]

That vertical ghosting effect that’s obvious in the picture 2nd from the bottom is unfortunately a common problem when refreshing HUB12 (And some HUB75 panels) quickly. I don’t have a solution for it.

[jvlopez]

Hi any news in slowing down the refresh for HUB12?