16x32 LED Matrix with Adafruit Library

I purchased a 1/4 scan 16x32 LED Matrix display from AliExpress (which is why I’m not posting this on the adafruit forum).

I use the Adafruit setup, and their library. The pinout matches the 32x32 configuration with a D pin.

The pixels all light up but in a stack of four instead of a single row.

If I use something like this:

#include <Adafruit_GFX.h>   // Core graphics library
#include <RGBmatrixPanel.h> // Hardware-specific library

// If your 32x32 matrix has the SINGLE HEADER input,
// use this pinout:
#define CLK 8  // MUST be on PORTB! (Use pin 11 on Mega)
#define OE  9
#define LAT 10
#define A   A0
#define B   A1
#define C   A2
#define D   A3
// If your matrix has the DOUBLE HEADER input, use:
//#define CLK 8  // MUST be on PORTB! (Use pin 11 on Mega)
//#define LAT 9
//#define OE  10
//#define A   A3
//#define B   A2
//#define C   A1
//#define D   A0
RGBmatrixPanel matrix(A, B, C, D, CLK, LAT, OE, false);

void setup() {

  matrix.begin();
  matrix.drawPixel(1,1,matrix.Color333(7,7,7));

}

void loop() {
  // do nothing
}

I get stack of 4 white LEDs, not a single pixel. It’s also not the top right corner.

Has anyone done this kind of modification of the library?

Don't you think a link to the display you purchased might be useful?

The pinout matches the 32x32 configuration with a D pin.

Do you mean it matches including the fact that it has a D pin, or it matches except that it has a D pin?

Thanks for using code tags. Read the forum sticky post to find out how to post links.

Here is the panel I purchased: AliExpress 16x32 Panel

Well, who can say if it is 1/4 scan or not? Clearly the seller does not understand what they are selling. For example it says:

Power Input AC110V/ 220V ±10, 50HZ

Do you think the board should be connected to mains AC?

Post your wiring diagram.

Obviously not.

No, nor do I.

Clearly this display is not wired the same internally as the Adafruit.

Your example sketch was supposed to light the led at coordinates 1,1 in white. But you get 4 LEDs lit. At what coordinates? And what colour(s)?

You said "The pixels all light up". Did you try every possible coordinate in the test sketch?. What other effects did you see, was there any pattern to them?

If I try out the 16x32 examples provided by Adafruit, all the pixels come on and flash in a variety of different colors. As far as I can tell, each software pixel translates to a column of four vertical hardware pixels. The colors work as expected.

Hmm...

Could you email the vendor and ask if they have a schematic?