80x40 P4 display pannel alignment problem

[rbensingh]

I have an 80x40 P4 display with a chain of 6 in series panels, currently I have removed the 5 panels and testing using a single panel.
I have attached the code and the images. the results are not as expected, kindly guide me with it.

#include <Arduino.h>
#include <ESP32-HUB75-VirtualMatrixPanel_T.hpp>

#define PANEL_RES_X 80
#define PANEL_RES_Y 40
#define VDISP_NUM_ROWS 1
#define VDISP_NUM_COLS 1
#define PANEL_CHAIN_LEN (VDISP_NUM_ROWS * VDISP_NUM_COLS) // Don't change
#define PANEL_CHAIN_TYPE CHAIN_NONE
#define PANEL_SCAN_TYPE FOUR_SCAN_40_80PX_HFARCAN

MatrixPanel_I2S_DMA* dma_display = nullptr;
using MyScanTypeMapping = ScanTypeMapping<PANEL_SCAN_TYPE>;
VirtualMatrixPanel_T<PANEL_CHAIN_TYPE, MyScanTypeMapping>* virtualDisp = nullptr;

void setup() {
Serial.begin(115200);
delay(500);

HUB75_I2S_CFG::i2s_pins _pins = {
WF2_X1_R1_PIN, WF2_X1_G1_PIN, WF2_X1_B1_PIN,
WF2_X1_R2_PIN, WF2_X1_G2_PIN, WF2_X1_B2_PIN,
WF2_A_PIN, WF2_B_PIN, WF2_C_PIN, WF2_D_PIN, WF2_X1_E_PIN,
WF2_LAT_PIN, WF2_OE_PIN, WF2_CLK_PIN
};

HUB75_I2S_CFG mxconfig(
PANEL_RES_X * 2, // physical width encoding
PANEL_RES_Y / 2, // physical height encoding
PANEL_CHAIN_LEN, // panel chain length
_pins);

mxconfig.i2sspeed = HUB75_I2S_CFG::HZ_20M;
mxconfig.clkphase = true;
mxconfig.line_decoder = HUB75_I2S_CFG::SM5368;

dma_display = new MatrixPanel_I2S_DMA(mxconfig);
dma_display->begin();
dma_display->setBrightness8(120);
dma_display->clearScreen();

virtualDisp = new VirtualMatrixPanel_T<PANEL_CHAIN_TYPE, MyScanTypeMapping>(
VDISP_NUM_ROWS, VDISP_NUM_COLS, PANEL_RES_X, PANEL_RES_Y);

virtualDisp->setDisplay(*dma_display);

for (int y = 0; y < virtualDisp->height(); y++) {
for (int x = 0; x < virtualDisp->width(); x++) {

  uint16_t color = virtualDisp->color565(96, 0, 0);  // red

  if (x == 0) color = virtualDisp->color565(0, 255, 0);                           // g
  if (x == (virtualDisp->width() - 1)) color = virtualDisp->color565(0, 0, 255);  // b

  virtualDisp->drawPixel(x, y, color);
  delay(1);
}

}

virtualDisp->drawLine(virtualDisp->width() - 1, virtualDisp->height() - 1, 0, 0, virtualDisp->color565(255, 255, 255));

virtualDisp->print("Virtual Matrix Panel");
delay(3000);
virtualDisp->clearScreen();
virtualDisp->drawDisplayTest(); // re draw text numbering on each screen to check connectivity
}

Thanks in advance.

https://github.com/user-attachments/assets/267414f4-442b-400f-bb82-63f8c8fd4d0d

[board707]

Please read the type of selected chips:

[rbensingh]

These are the part numbers

[board707]

Thanks.
The good news that your matrix has a chips compatible with the library.

Now you need to take a Pixel_Mapping_Test library example and make a two changes on it:

1. Replace CustomPxBasePanel ::getCoords() method with the code below:

inline VirtualCoords CustomPxBasePanel  ::getCoords(int16_t x, int16_t y) {

  coords = VirtualMatrixPanel::getCoords(x, y); // first call base class method to update coords for chaining approach

  if ( coords.x == -1 || coords.y == -1 ) { // Co-ordinates go from 0 to X-1 remember! width() and height() are out of range!
    return coords;
  }


  uint8_t pxbase = 80;  // pixel base
  if ((coords.y  % 20 ) < 10)
  {
    coords.x += (coords.x / pxbase + 1) * pxbase;
  }
  else
  {
    coords.x += (coords.x / pxbase) * pxbase; // 2nd, 4th 'block' of 8 rows of pixels, offset by panel width in DMA buffer
  }

  coords.y = (coords.y /20 ) * 10 + (coords.y % 10);

  return coords;
}

2. Add the line
   mxconfig.line_decoder = HUB75_I2S_CFG::SM5368;
   just after line 110
   mxconfig.clkphase = false;

Then run the code and show the video.

(Take note that it is not a final solution, but just a test)

[rbensingh]

Thank you for your response

i have attached the code and the video

Note: I have cropped the video to reduce the size of upload, the LED 'S are turned on sequentially

Trimmed.mp4

/*************************************************************************
Description:

The underlying implementation of the ESP32-HUB75-MatrixPanel-I2S-DMA only
supports output to HALF scan panels - which means outputting
two lines at the same time, 16 or 32 rows apart if a 32px or 64px high panel
respectively.
This cannot be changed at the DMA layer as it would require a messy and complex
rebuild of the library's internals.

However, it is possible to connect QUARTER (i.e. FOUR lines updated in parallel)
scan panels to this same library and
'trick' the output to work correctly on these panels by way of adjusting the
pixel co-ordinates that are 'sent' to the ESP32-HUB75-MatrixPanel-I2S-DMA
library.

**************************************************************************/

/* Use the Virtual Display class to re-map co-ordinates such that they draw
correctly on a 32x16 1/4 or 64x32 1/8 Scan panel (or chain of such panels).
*/
#include "ESP32-VirtualMatrixPanel-I2S-DMA.h"

// Define custom class derived from VirtualMatrixPanel
class CustomPxBasePanel : public VirtualMatrixPanel {
public:
using VirtualMatrixPanel::VirtualMatrixPanel; // inherit VirtualMatrixPanel's constructor(s)

protected:

VirtualCoords getCoords(int16_t x, int16_t y); // custom getCoords() method for specific pixel mapping
};

inline VirtualCoords CustomPxBasePanel ::getCoords(int16_t x, int16_t y) {

coords = VirtualMatrixPanel::getCoords(x, y); // first call base class method to update coords for chaining approach

if (coords.x == -1 || coords.y == -1) { // Co-ordinates go from 0 to X-1 remember! width() and height() are out of range!
return coords;
}

uint8_t pxbase = 80; // pixel base
if ((coords.y % 20) < 10) {
coords.x += (coords.x / pxbase + 1) * pxbase;
} else {
coords.x += (coords.x / pxbase) * pxbase; // 2nd, 4th 'block' of 8 rows of pixels, offset by panel width in DMA buffer
}

coords.y = (coords.y / 20) * 10 + (coords.y % 10);

return coords;
}

// Panel configuration
#define PANEL_RES_X 80 // Number of pixels wide of each INDIVIDUAL panel module.
#define PANEL_RES_Y 40 // Number of pixels tall of each INDIVIDUAL panel module.

// Use a single panel for tests
#define NUM_ROWS 1 // Number of rows of chained INDIVIDUAL PANELS
#define NUM_COLS 1 // Number of INDIVIDUAL PANELS per ROW

// Chain settings, do not cnahge
#define SERPENT true
#define TOPDOWN false
#define VIRTUAL_MATRIX_CHAIN_TYPE CHAIN_BOTTOM_RIGHT_UP

// placeholder for the matrix object
MatrixPanel_I2S_DMA *dma_display = nullptr;

// placeholder for the virtual display object
CustomPxBasePanel *FourScanPanel = nullptr;

#define WF2_X1_R1_PIN 2
#define WF2_X1_R2_PIN 3
#define WF2_X1_G1_PIN 6
#define WF2_X1_G2_PIN 7
#define WF2_X1_B1_PIN 10
#define WF2_X1_B2_PIN 11
#define WF2_X1_E_PIN 21

#define WF2_X2_R1_PIN 4
#define WF2_X2_R2_PIN 5
#define WF2_X2_G1_PIN 8
#define WF2_X2_G2_PIN 9
#define WF2_X2_B1_PIN 12
#define WF2_X2_B2_PIN 13
#define WF2_X2_E_PIN -1 // Currently unknown, so X2 port will not work (yet) with 1/32 scan panels

#define WF2_A_PIN 39
#define WF2_B_PIN 38
#define WF2_C_PIN 37
#define WF2_D_PIN 36

#define WF2_OE_PIN 35
#define WF2_CLK_PIN 34
#define WF2_LAT_PIN 33

#define WF2_BUTTON_TEST 17 // Test key button on PCB, 1=normal, 0=pressed
#define WF2_LED_RUN_PIN 40 // Status LED on PCB
#define WF2_BM8563_I2C_SDA 41 // RTC BM8563 I2C port
#define WF2_BM8563_I2C_SCL 42
#define WF2_USB_DM_PIN 19
#define WF2_USB_DP_PIN 20

HUB75_I2S_CFG::i2s_pins _pins = {
WF2_X1_R1_PIN, WF2_X1_G1_PIN, WF2_X1_B1_PIN,
WF2_X1_R2_PIN, WF2_X1_G2_PIN, WF2_X1_B2_PIN,
WF2_A_PIN, WF2_B_PIN, WF2_C_PIN, WF2_D_PIN, WF2_X1_E_PIN,
WF2_LAT_PIN, WF2_OE_PIN, WF2_CLK_PIN
};

/******************************************************************************
Setup!
******************************************************************************/
void dissetup() {
HUB75_I2S_CFG mxconfig(
PANEL_RES_X * 2, // DO NOT CHANGE THIS
PANEL_RES_Y / 2, // DO NOT CHANGE THIS
NUM_ROWS * NUM_COLS // DO NOT CHANGE THIS
,
_pins // Uncomment to enable custom pins
);

mxconfig.clkphase = false; // Change this if you see pixels showing up shifted wrongly by one column the left or right.
mxconfig.line_decoder = HUB75_I2S_CFG::SM5368;

// OK, now we can create our matrix object
dma_display = new MatrixPanel_I2S_DMA(mxconfig);

// let's adjust default brightness to about 75%
dma_display->setBrightness8(40); // range is 0-255, 0 - 0%, 255 - 100%

// Allocate memory and start DMA display
if (not dma_display->begin())
Serial.println("****** !KABOOM! I2S memory allocation failed ***********");

dma_display->clearScreen();
delay(500);

// create FourScanPanellay object based on our newly created dma_display object
FourScanPanel = new CustomPxBasePanel((*dma_display), NUM_ROWS, NUM_COLS, PANEL_RES_X, PANEL_RES_Y, VIRTUAL_MATRIX_CHAIN_TYPE);

disloop();
FourScanPanel->drawDisplayTest();
}

void disloop() {
for (int i = 0; i < FourScanPanel->height(); i++) {
for (int j = 0; j < FourScanPanel->width(); j++) {
FourScanPanel->drawPixel(j, i, FourScanPanel->color565(255, 0, 0));
delay(30);
}
}
delay(2000);
dma_display->clearScreen();
} // end loop

[board707]

Thanks.
Now set the pxbase to 40:
uint8_t pxbase = 40; // pixel base
inside a getCoords() method

[rbensingh]

Thanks
Now i have changed the pxbase to 40, and here is the video

pixelbase40.mp4

[board707]

@rbensingh
I apologize, but I didn't look closely enough at your first video (where the pxbase was 80). I was misled by the fact that you have a screen with multiple panels.
Upon closer inspection, you can see that the first panel is sequentially filled with pixels. This means the mapping is correct, and if you're having any issues with the panel, the problem lies elsewhere.
Please explain in more detail what's not working.

[rbensingh]

Thank you for response and my apologies for late reply.

The code is working fine with the below setup,

inline VirtualCoords CustomPxBasePanel ::getCoords(int16_t x, int16_t y) {
coords = VirtualMatrixPanel::getCoords(x, y); // first call base class method to update coords for chaining approach
if (coords.x == -1 || coords.y == -1) { // Co-ordinates go from 0 to X-1 remember! width() and height() are out of range!
return coords;
}
uint8_t pxbase = 80; // pixel base
if ((coords.y % 20) < 10) {
coords.x += (coords.x / pxbase + 1) * pxbase;
} else {
coords.x += (coords.x / pxbase) * pxbase; // 2nd, 4th 'block' of 8 rows of pixels, offset by panel width in DMA buffer
}
coords.y = (coords.y / 20) * 10 + (coords.y % 10);
return coords;
}