P5 HUB75 64x32 matrix - noisy output and wrong colors displayed, chaining not working

[BodoMinea]

Hi everyone,

I have this panel - https://www.aliexpress.com/item/32998526924.html bought from Aliexpress that I can easily control with an Arduino Mega 2560 following the guide on Adafruit and also using their library - https://learn.adafruit.com/32x16-32x32-rgb-led-matrix/connecting-with-jumper-wires / https://github.com/adafruit/RGB-matrix-Panel

It works with their default configuration and examples, but only one 64x32 matrix (no chaining).

I am also able to correctly control it with the default settings in @hzeller´s https://github.com/hzeller/rpi-rgb-led-matrix With that, chaining also works (even with 6 of them).

Now, here are my results with PxMatrix.

1. Post your code The code is probably NOT the issue. I can use it with other LED matrix panels I have (a P4 64x32 for example), but anyway.

#include <PxMatrix.h>

#define P_LAT 22
#define P_A 19
#define P_B 23
#define P_C 18
#define P_D 5
#define P_E 15
#define P_OE 16
hw_timer_t * timer = NULL;
portMUX_TYPE timerMux = portMUX_INITIALIZER_UNLOCKED;

#define matrix_width 64
#define matrix_height 32

// This defines the 'on' time of the display is us. The larger this number,
// the brighter the display. If too large the ESP will crash
uint8_t display_draw_time=70; //30-70 is usually fine

//PxMATRIX display(,16,P_LAT, P_OE,P_A,P_B,P_C);
PxMATRIX display(64,32,P_LAT, P_OE,P_A,P_B,P_C,P_D);
//PxMATRIX display(64,64,P_LAT, P_OE,P_A,P_B,P_C,P_D,P_E);

// Some standard colors
uint16_t myRED = display.color565(255, 0, 0);
uint16_t myGREEN = display.color565(0, 255, 0);
uint16_t myBLUE = display.color565(0, 0, 255);
uint16_t myWHITE = display.color565(255, 255, 255);
uint16_t myYELLOW = display.color565(255, 255, 0);
uint16_t myCYAN = display.color565(0, 255, 255);
uint16_t myMAGENTA = display.color565(255, 0, 255);
uint16_t myBLACK = display.color565(0, 0, 0);

uint16_t myCOLORS[8]={myRED,myGREEN,myBLUE,myWHITE,myYELLOW,myCYAN,myMAGENTA,myBLACK};

void IRAM_ATTR display_updater(){
  // Increment the counter and set the time of ISR
  portENTER_CRITICAL_ISR(&timerMux);
  display.display(display_draw_time);
  portEXIT_CRITICAL_ISR(&timerMux);
}

void display_update_enable(bool is_enable)
{

  if (is_enable)
  {
    timer = timerBegin(0, 80, true);
    timerAttachInterrupt(timer, &display_updater, true);
    timerAlarmWrite(timer, 4000, true);
    timerAlarmEnable(timer);
  }
  else
  {
    timerDetachInterrupt(timer);
    timerAlarmDisable(timer);
  }
}

void setup() {
  display.begin(16);

  display.setScanPattern(LINE);

  //display.setPanelsWidth(2);

  display.clearDisplay();
  display.setTextColor(myCYAN);
  display.setCursor(2,0);
  display.print("abcdefghijklmnop");

  display_update_enable(true);

  delay(5000);

}

unsigned long last_draw=0;
void scroll_text(uint8_t ypos, unsigned long scroll_delay, String text, uint8_t colorR, uint8_t colorG, uint8_t colorB)
{
    uint16_t text_length = text.length();
    display.setTextWrap(false);  // we don't wrap text so it scrolls nicely
    display.setTextSize(1);
    display.setRotation(0);
    display.setTextColor(display.color565(colorR,colorG,colorB));

    // Asuming 5 pixel average character width
    for (int xpos=matrix_width; xpos>-(matrix_width+text_length*5); xpos--)
    {
      display.setTextColor(display.color565(colorR,colorG,colorB));
      display.clearDisplay();
      display.setCursor(xpos,ypos);
      display.println(text);
      delay(scroll_delay);
      yield();

      // This might smooth the transition a bit if we go slow
      // display.setTextColor(display.color565(colorR/4,colorG/4,colorB/4));
      // display.setCursor(xpos-1,ypos);
      // display.println(text);

      delay(scroll_delay/5);
      yield();

    }
}

void loop() {
  scroll_text(1,50,"Welcome to PxMatrix!",96,96,250);
  display.clearDisplay();
}

2. Post a picture of the problem and describe what you expect to see With the code above, I currently see this: (and the scrolling text shows up as white and very noisy).

If I uncomment the display.setPanelsWidth(2); and chain another panel (ESP32 to Panel Input of matrix 1, from there to panel output of matrix 2 and a ribbon connecting all pins of panel output 1 to panel input 2), this is the result - still only the first (ESP32 directly connected) panel lights up, and it displays like this:

Seller instructions say it is a 1/16 scan module, but I tested to see how it looks with 1/8 just to be sure (no chaining, only one module):

3. Run the pattern test and post the result as gif/video (need to have a bit more than one full RED/YELLOW/WHITE cycle)

1/16 pattern test (it loops after WHITE) - please note that the GIF skips some frames, but the pattern test fully runs, smoothly. Here it also doesn't have the noise issues I get on the pixeltime sketch: 1/8 pattern test (it stops/locks up after WHITE):

During both tests only one module is connected.

4. State what version of PxMatrix you are running and what MicroController you use Latest PxMatrix with ESP-WROOM-32. The wiring is the standard one from the project homepage, with some of the PI wires hooked up to the PO and the rest to the ESP32 via jumper cables. I have tried swapping out cables, boards, re-setting-up and recompiling everything on ESP8266, the results are the same, can't get it to display correctly.

Any ideas are appreciated. Happy holidays!

[davecorbett1961]

Hello! Did you ever get this issue resolved? I have a very similar problem I think. I have a single 1/16 P5 64x32 panel which works fine using an Arduino Mega 2560 following the guide on https://github.com/adafruit/RGB-matrix-Panel. But I want chaining of multiple panels so I have wired it to a D1 mini clone as per instructions on https://github.com/2dom/PxMatrix. The pattern test runs mostly ok but the "pixeltime" test has serious ghosting. AFAIK the wiring is correct. Any ideas?

[BodoMinea]

Hi, the mentioned matrix works properly with another and different wiring - try using this https://github.com/pixelmatix/SmartMatrix

The wiring should be documented as a comment in the corresponding example sketches or you can check out some more details in this project - https://esp32.com/viewtopic.php?f=17&t=3188 or on the library wiki http://docs.pixelmatix.com/SmartMatrix/library.html

You can also check out some discussions on the library forum - https://community.pixelmatix.com/ I got multiple types of non standard panels with the help of folks over there.

Good luck with your project!