I have a BT817 from Riverd like that you refer to, so far it has worked very well with the GDSTx library in teensy 4.1.

In order to experiment with that situation that you mention, you will have a guide on how to use your library in the arduino ide environment (preferably 1.8.19, since 2 seems to me to be an unfinished job and with many errors still), wiring, and what extra device is required to be able to use the onboard flash memory that the display has?

Thanks for taking some time.

The library for gameduino 23x has the file wiring.h as its axis of operation, within that file the starting of the EVEx chips occurs.

This is the library I've been testing with: GDSTx. You just have to place it in the libraries folder of the arduino IDE.

I uploaded the video examples, as evidence that it is possible to draw arc segments, not to test them; As I said, I have spent several years trying to understand the library and adapt it to be able to use it with teensy 4.1 and especially with its SDIO reader. Over time there have been several versions of the library, which is why I decided to upload the changes to Github to always have a backup. Unfortunately several examples were lost, when the hard drive I was working on failed a couple of years ago; only youtube videos remained.

I apologize for not being able to share the complete examples or the libraries, as I no longer have them.

I share the example for drawing arc segments, which resulted from all those experiments.

I've been modifying the library for gameduino 2 for some time with the permission of the good James Bowman, to be able to adapt it to STM32 or teensy 4/4.1 boards; with the idea of ​​being able to apply the full potential of the library with faster MCUs than AVRs. The project is called GDSTx, the repository is on Github.

In a chat with chatGPT, with the idea of ​​fine-tuning some parts of the project I'm working on, I asked him to indicate what the code would be like to draw an arc of variable length, using GDSTx, after an exchange of corrections, this was the result:

#include <GDSTx.h>

long previousMillis = 0;
long intervalo = 250;
int valor=0;

void setup()
{
  GD.begin();
}
void loop()
{
  GD.ClearColorRGB(0x100020);
  GD.Clear();

  GD.SaveContext(); //Guardamos los parámetros de color y transparencia
  GD.Begin(LINE_STRIP);
  GD.ColorRGB(0xFFFFFF); //Color del arco
  int x, y;
  unsigned long currentMillis = millis();       
  if(currentMillis - previousMillis > intervalo)
  {
   previousMillis = currentMillis;         
   valor=GD.random(0,359);
  }
   
  for (int i = 0; i <= valor; i++) {
    x = 400 + 100 * cos(i * PI/180 );
    y = 240 + 100 * sin(i * PI/180 );
    GD.Vertex2f(16*x, 16*y); //Se ajustan las dimensiones en pantalla
  }
  GD.RestoreContext(); //Restauramos los parámetros de color y transparencia

  GD.SaveContext(); //Guardamos los parámetros de color y transparencia
  GD.ColorRGB(0xFFFFFF); //Color del texto
  GD.cmd_text(0, 455, 26, 0, "Coded by chatGPT/FT81xmania"); //Texto del título
  GD.RestoreContext(); //Restauramos los parámetros de color y transparencia

  GD.swap();
}

In relation to the library to control screens of the EVEx families, the version I have worked on for some years is this: GDSTx

I chose to center it on teensy 4 and 4.1 MCU, although it can also work with 3.5 and 3.6. With 3.2 it works to a limited extent, since I haven't found a way to use the SdFat library with a reader on the SPI bus. It also works with STM32 boards, setting the proper pins for each board for correct access to the microSD reader, on a secondary SPI bus, the TFT goes on SPI-1.

The screens with which I have been able to test it are:

- FT813: 3.5, 4.3 and 5" NHD
- BT815: 5" Matrix Orbital
- BT817: 5" Riverdi
- FT800: 4.3" FT843 4DSystems

Regarding STM32, these are the boards that I have been able to test: Black F407VG, Black F411CE, Core7XXI (F746), F767 core, bluePill C103, M4-DEMO (F407ZG), M3-DEMO (F103ZG) and F429-DISCO.


MCU: Teensy 4.1@528MHz
TFT: EVE-50G (BT815, 5", Matrix Orbital)

You must specify the exact TFT you have, since those time tables come in your datasheet. Although the graphics chip is an EVEx, the screen used by the manufacturer has its own vertical and horizontal synchronization parameters, for that reason they must be added to the library. As Rudolph points out, he has been able to work with many variants of EVEx displays, but experience dictates that each display has specific parameters to make it work.

As the seeeduino board you have compiles without errors the code exported from ESE to gameduino, it will only be enough to add that time table to the ccp file of the library.

Share the link to the exact variant of your screen, from there you can review the datasheet to obtain the specific time tables.

That error has to do with your MCU, maybe the data cable is bad, maybe your MCU doesn't have enough power to run the display you want to connect.

Try another data cable but without connecting the screen.

Some time ago I saw that it is possible to use the library for gameduino 2 with the EVE screens (FT800 and FT801), in fact the EVE Screen Editor (4.2.0) can export sketches with that library; so together with a friend (lightcalamar) we got to work (rather in the code) to investigate if it was possible to use screens like the EVE2 (FT813), EVE3 (BT815) or the EVE4 (BT817). With permission from its author: James Bowmann, we managed to modify the library for gameduino 23X, so that it could be used in conjunction with the SdFat library, instead of the SD library, all in the Arduino IDE environment.

The library is focused on STM32 boards like F103, F407, F411, F429, F746 and F767 and mainly on teensy 3.6, 4 and 4.1. The AVR and Due boards are very, very limited with the SdFat library, so we've left them out. At the moment the flash memory part has not been explored, however the other functions can be used perfectly.

The most advanced library we have is the GDSTx, however it needs some adjustments to upload it to github. The previous version is GDT4Xv134

Reviewing the way EVE Screen Editor v4.2.0 exports via pyton, I was able to add the option to export to the GDSTx custom library on FT81x boards (10, 11, 12 and 13), but with BT81x boards it hasn't been possible to get it. If the administrators allow it, I could share the modified program.

The screens I'm using are the NHD-FT813 5" on Teensy 4.1


And the Riverdi BT817 5" on Teensy 4.1