Support for ESP32-S2

[Pipimaxi]

Hello community,
does anybody play with this library succesfully on a ESP32-S2 device?
I am trying to get several HUB75 displays working with a Saola board, but without success....but I am very close!
Compilation is working, toggling of the parallel bus is also working, but the result is....not correct :-D
DrawPixel(0,0), everything is off
Drawpixel(1,0), both first LEDs in the upper row are switched on.
In my opinion, there is something different in the DMA device between ESP32 and ESP32-S2, because I2S driver is working correctly, I think, and this behaviour is also with SmartMatrix Library, so I would expect the last hurdle in DMA or maybe I2S section.
Any experiances with ESP32-S2?

Thanks in advance!
BR
Markus

[mrcodetastic]

Can you try this branch of the library to see if it helps? https://github.com/mrfaptastic/ESP32-HUB75-MatrixPanel-I2S-DMA/tree/SM5266P

Also make sure you have looked at the 'common issues' issue to see if any panel config settings might help there.

[Pipimaxi]

Hi,
unfortunately the branch SM5266P didn't solve the problem.
I share you some pictures, captured with logicanalyzer and the corresponding result of the led matrix.
In the detailled picture Pixel_1_1 you can see the shift-out of the data one timeslot before the addressline is switching. Maybe this could be the issue?

[Pipimaxi]

SM5266P is no case for me at the moment :D
Setting correct frequency seems to be OK right now, the only problem is the doubling.
I want to share "the" solution if the doubling is also fixed, dont worry.
Is there any relation between CLK signal and, for example, B1 pin?

[mrcodetastic]

The output of B1 like any of the other colour pins is determined by what you want displayed.

If the problem is only with B1 then I have no idea. What happens if you light up red or and green at the same time as well? They should all be exactly the same.

[Pipimaxi]

Yes sorry, I ment all six color lines in relation to CKL signal. Why the same data is shifted out twice

[mrcodetastic]

I have no idea but I think it's definitely DMA config stuff. Have you played with the i2s_dma.....c file I mentioned previously?

A read of the technical reference manual under the DMA and I2S sections may give clues. I don't have an S2 so can't trial and error a solution.

[mrcodetastic]

Try the branch I created of this library. Did it work?

[vortigont]

A piece of config code how are you running this could've helped a lot. Seems to me doubling is just shifting the same data further in the chain.
Are you using this config?

cfg.mx_width=32
mxconfig.mx_height = 32;
mxconfig.chain_length = 2;

[Pipimaxi]

That would be to easy ;-)
Regarding ESP32-S2 branch:
Not in total, because I used the i2s-dma setup function from SmartMatrix project, "your" setup function didnt work without "deeper" investigations.
I uploaded all relevant functions to github, I hope you have access:
https://gist.github.com/Pipimaxi/e6b467333417f0ca02000b6b44406352

Maybe its a bit easier to watch in the code directly.

[mrcodetastic]

Well, other than commenting out dev->clkm_conf.clk_sel = 2; and playing with the other values, not sure I can help.

Keep experimenting with random clock dividers and hopefully you'll find the solution!

[vortigont]

Seems that your clock rate is either twice as fast as data - than you get double dots in series, or twice as slower - than you have clones every row/2. Try to play with dev->conf2.lcd_tx_wrx2_en and dev->sample_rate_conf.tx_bck_div_num
A scope captures for plotting not series but every even/odd dot might give you a better clue here.

[Pipimaxi]

So, new News....
Playing with wrx2 and bck_div has no effect.
I also recognized following:
Pixel(0,0), no LED is on, Pixel (1,0) the LED (0,0) is on
Pixel(2,0) no LED is on, Pixel(3,0) the LED (1,0) is on
And so on....
Stepping through all rows is no problem, only the coloumn is the problem
Display is still doubled...
If no LED is switched on although DrawPixel is called, there is also no activity on B1 Pin
The focus is now really on DMA side I think...

[mrcodetastic]

sp32-s2_technical_reference_manual_en.pdf is your friend.

There's a whole bunch of stuff you can change, and most of them we can't test as they're only available on the ESP32-S2 IDF.

Page 680

I2S Output Format When I2S_TX_CHAN_MOD[2:0] = 0 and I2S_TX_DMA_EQUAL = 0

Best of luck!

[Pipimaxi]

so, next chapter in my never-end story ...
Yesterday I played with some I2S_TX_CHAN_MOD values together with I2S_TX_DMA_EQUAL
The best resultis I2S_TX_DMA_EQUAL=1 with I2S_TX_CHAN_MOD=0-2
According to the technical ref manual it doesnt matter if its 0...1 or 2
But it seems there is still a shift in the stream for the LED matrix:
DrawPixel(0,0):

DrawPixel(1,0):

DrawPixel(2,0):

DrawPixel(62,0):

The capture from the logic analyzer will confirm this behaviour:
DrawPixel(0,0):

DrawPixel(62,0):

Adding blanks for LAT changes nothing, also changing the clockphase gives any positive result.
Would that mean that the complete calculation of setting pixels in the DMA stream has to be reworked?

[mrcodetastic]

Two things:

• That clock signal is completely stuffed
• And I didn't realise you'd published a gist with a bunch of changes. I've taken a look and made some changes:

Please Try: https://github.com/mrfaptastic/ESP32-HUB75-MatrixPanel-I2S-DMA/tree/ESP32-S2

In summary, I think the clock divider you had is wrong, and there's some other things that may needed to be put in place according to the technical reference manual, which I have done.

[Pipimaxi]

OK, so tried your code or your S2-branch
After some compilation errors according different names in i2s structure, the behaviour is the same as in my code.
I dont think this issue is based on wrong clock configuration. Yes, the frequency will differ, but the issue is still the same.
The gap between LAT and the B1 or "color-pin" is not 3 edges in every time, you can see this in my video (switch audio on, sometimes I am talking which LED should be switched on ;-) )
https://user-images.githubusercontent.com/12627751/130296683-1a3e245f-9a9e-4b30-b931-9bcfca8c6fc2.mp4

"dev->conf.tx_big_endian = 1; // MIGHT NEED TO CHANGE THIS!!" <<--- you have to change this to 0, otherwise the whole 16bit-bus will be swapped.
If you want I can send you a ESP32-S2 Saola Dev Board...maybe this is better than change any code via trial and error without hardware...

[mrcodetastic]

Thanks for the ESP32-S2. I have fixed the problem with the ESP32-S2 and will try and merge into the main tree at some point.

Grab it here: https://github.com/mrfaptastic/ESP32-HUB75-MatrixPanel-I2S-DMA/tree/ESP32-S2-dev

Test it with.

// Example sketch which shows how to display some patterns
// on a 64x32 LED matrix
//

#include <ESP32-HUB75-MatrixPanel-I2S-DMA.h>


#define PANEL_RES_X 64      // Number of pixels wide of each INDIVIDUAL panel module. 
#define PANEL_RES_Y 32     // Number of pixels tall of each INDIVIDUAL panel module.
#define PANEL_CHAIN 1      // Total number of panels chained one to another
 
//MatrixPanel_I2S_DMA dma_display;
MatrixPanel_I2S_DMA *dma_display = nullptr;

uint16_t myBLACK = dma_display->color565(0, 0, 0);
uint16_t myWHITE = dma_display->color565(255, 255, 255);
uint16_t myRED = dma_display->color565(255, 0, 0);
uint16_t myGREEN = dma_display->color565(0, 255, 0);
uint16_t myBLUE = dma_display->color565(0, 0, 255);



// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
// From: https://gist.github.com/davidegironi/3144efdc6d67e5df55438cc3cba613c8
uint16_t colorWheel(uint8_t pos) {
  if(pos < 85) {
    return dma_display->color565(pos * 3, 255 - pos * 3, 0);
  } else if(pos < 170) {
    pos -= 85;
    return dma_display->color565(255 - pos * 3, 0, pos * 3);
  } else {
    pos -= 170;
    return dma_display->color565(0, pos * 3, 255 - pos * 3);
  }
}

void drawText(int colorWheelOffset)
{
  
  // draw text with a rotating colour
  dma_display->setTextSize(1);     // size 1 == 8 pixels high
  dma_display->setTextWrap(false); // Don't wrap at end of line - will do ourselves

  dma_display->setCursor(5, 0);    // start at top left, with 8 pixel of spacing
  uint8_t w = 0;
  const char *str = "ESP32 DMA";
  for (w=0; w<strlen(str); w++) {
    dma_display->setTextColor(colorWheel((w*32)+colorWheelOffset));
    dma_display->print(str[w]);
  }

  dma_display->println();
  dma_display->print(" ");
  for (w=9; w<18; w++) {
    dma_display->setTextColor(colorWheel((w*32)+colorWheelOffset));
    dma_display->print("*");
  }
  
  dma_display->println();

  dma_display->setTextColor(dma_display->color444(15,15,15));
  dma_display->println("LED MATRIX!");

  // print each letter with a fixed rainbow color
  dma_display->setTextColor(dma_display->color444(0,8,15));
  dma_display->print('3');
  dma_display->setTextColor(dma_display->color444(15,4,0));
  dma_display->print('2');
  dma_display->setTextColor(dma_display->color444(15,15,0));
  dma_display->print('x');
  dma_display->setTextColor(dma_display->color444(8,15,0));
  dma_display->print('6');
  dma_display->setTextColor(dma_display->color444(8,0,15));
  dma_display->print('4');

  // Jump a half character
  dma_display->setCursor(34, 24);
  dma_display->setTextColor(dma_display->color444(0,15,15));
  dma_display->print("*");
  dma_display->setTextColor(dma_display->color444(15,0,0));
  dma_display->print('R');
  dma_display->setTextColor(dma_display->color444(0,15,0));
  dma_display->print('G');
  dma_display->setTextColor(dma_display->color444(0,0,15));
  dma_display->print("B");
  dma_display->setTextColor(dma_display->color444(15,0,8));
  dma_display->println("*");

}

#define R1_PIN  7
#define G1_PIN  42
#define B1_PIN  41
#define R2_PIN  40
#define G2_PIN  39
#define B2_PIN  38
#define A_PIN 37
#define B_PIN 36
#define C_PIN 35
#define D_PIN 34
#define E_PIN -1 // required for 1/32 scan panels, like 64x64. Any available pin would do, i.e. IO32
#define LAT_PIN 8
#define OE_PIN  9
#define CLK_PIN 6


void setup() {

  Serial.begin(230400);
  Serial.println(""); Serial.println(""); Serial.println("");
  Serial.println("*****************************************************");
  Serial.println(" HELLO !");
  Serial.println("*****************************************************");
 
  HUB75_I2S_CFG::i2s_pins _pins={R1_PIN, G1_PIN, B1_PIN, R2_PIN, G2_PIN, B2_PIN, A_PIN, B_PIN, C_PIN, D_PIN, E_PIN, LAT_PIN, OE_PIN, CLK_PIN};
  HUB75_I2S_CFG mxconfig
  (
    PANEL_RES_X,   // module width
    PANEL_RES_Y,   // module height
    PANEL_CHAIN,   // chain length
    _pins
  );
  mxconfig.clkphase = false;
  mxconfig.latch_blanking = 1;
  
  
  dma_display = new MatrixPanel_I2S_DMA(mxconfig);
  dma_display->setBrightness8(50);    // range is 0-255, 0 - 0%, 255 - 100%
  
  if( not dma_display->begin() )
      Serial.println("****** !KABOOM! I2S memory allocation failed ***********");

  Serial.println( "Done" );

  dma_display->fillScreen(dma_display->color565(128,128,128));
  
  
  // fix the screen with green
  dma_display->fillRect(0, 0, dma_display->width(), dma_display->height(), dma_display->color444(0, 15, 0));
  delay(500);

  // draw a box in yellow
  dma_display->drawRect(0, 0, dma_display->width(), dma_display->height(), dma_display->color444(15, 15, 0));
  delay(500);

  // draw an 'X' in red
  dma_display->drawLine(0, 0, dma_display->width()-1, dma_display->height()-1, dma_display->color444(15, 0, 0));
  dma_display->drawLine(dma_display->width()-1, 0, 0, dma_display->height()-1, dma_display->color444(15, 0, 0));
  delay(500);

  // draw a blue circle
  dma_display->drawCircle(10, 10, 10, dma_display->color444(0, 0, 15));
  delay(500);

  // fill a violet circle
  dma_display->fillCircle(40, 21, 10, dma_display->color444(15, 0, 15));
  delay(500);

  // fill the screen with 'black'
  dma_display->fillScreen(dma_display->color444(0, 0, 0));

  //drawText(0);

  Serial.println("Done");

}

uint8_t wheelval = 0;

uint8_t wheelval2 = 0;

void loop() {
 dma_display->clearScreen();
  Serial.println(wheelval);
 // 
//  wheelval = 0;
  dma_display->drawLine(wheelval,0,wheelval,32,dma_display->color565(255, 255, 0));

  //wheelval = 0;
  dma_display->drawLine(64,0,64,32,dma_display->color565(255, 255, 0));
    
  wheelval++;
  if (wheelval > 64) wheelval = 0;

  dma_display->drawLine(1,wheelval2,62,wheelval2,dma_display->color565(0, 0, 255));
  wheelval2++;
  if (wheelval2 > 32) wheelval2 = 0;  
  
  // animate by going through the colour wheel for the first two lines
  drawText(0);
  delay(25);
}

VID_20210903_230708701.mp4

Thanks for the S2.

[mrcodetastic]

Not surprising. It's pretty much a totally different chip at the hardware level. Clearly they've kept the 'ESP32' name for marketing purposes.

[mrcodetastic]

@Pipimaxi

Can you do me a favour if you have a minute and try this branch as well? It should be a drop-in replacement for the current s2 branch.

https://github.com/mrfaptastic/ESP32-HUB75-MatrixPanel-I2S-DMA/tree/386SX-33

[Pipimaxi]

Yes, I think I am be able to test this branch this week
btw: did you tried the double buffer functionality with this S2 device?
Once I've tried this I got panic errors from the ESP during runtime or calling flipbuffer function.

[mrcodetastic]

I never tested that. I can't think of an obvious reason it causes a panic. I'll do some debugging with the S2

[mrcodetastic]

I don't get any crash or issues with double buffering enabled and using dma_display->flipDMABuffer(); using 386SX-33 branch.

Start of loop() looks like this:

void loop() {
 dma_display->flipDMABuffer(); 
 delayMicroseconds(200); // tiny delay to ensure ESP output has been flipped.
 dma_display->clearScreen();
  Serial.println(wheelval);
 <other code omitted>