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GDSTx library in teensy 4.1 (teensyduino 1.60-beta2) and NHD 5" FT813, Arduino IDE 1.8.19. Loaded from the SDIO reader using SdFat V2.2.3. The memory used is a 256Gb Canvas Go Plus microSD, formatted in exFat. The two png files appear normal

I'm keeping an eye on this new BT822 chip. 

Has memory been increased from 1 Mb to 1 Gb on the new BT822?

I have been a fan of EVE chips for years, who has directed his efforts to thoroughly explore the 23X gameduino library, created by James Bowman. So far it has worked on FT800/FT801, FT81x and BT81x; I ask you so excited that I can barely type on the keyboard... will it be possible to use this new BT822 with the gameduino 23X library?

PD: If the GPS that I have built and improved for several years with an FT813 chip, has been able to handle things that I had been told could not be achieved... I can already imagine what can be achieved with 1 Gb of memory!!!!

https://www.youtube.com/watch?v=ni0_DRU5PAQ

They are improved variants of the first EVE: FT800/FT801, with the ability to play avi/jpg encoded videos and with the possibility of rotating the screen content; such as FT81x/BT81x series.

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?

What library are you using with your screen?

It seems to me that you should adjust the rotation of the TFT and its dimensions, immediately after the restart of the coprocessor

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.

That example was only an approximation with simple mathematics, the editor can only handle basic things, more advanced examples can be achieved with relatively few instructions, but with slightly more complex mathematics that must consider that the TFT has the Y axis reference frame on the contrary, we must not forget that the EVEx graphics chip does all the drawing work, leaving the MCU only the calculation part.

MCU: teensy 3.6
TFT: NHD 5" FT813
Library: GDSTx (2023)
https://www.youtube.com/watch?v=LmyN9tgATtc

MCU: Nucleo STM32F767ZI
TFT: Riverdi FT813 5"
https://www.youtube.com/watch?v=Yb60PmJu5S0

MCU: Arduino Due
TFT: 4DSystem FT843 4.3" (FT800)
Library: gameduino 2
https://www.youtube.com/watch?v=FOhaWL84bKU

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();
}

I have noticed when connecting screens like the FT813, on AVR boards like the MEGA, the 3.3V regulator turns out to be not so efficient, from 5" the power demand by the backlight begins to make the MCU suffer. I have seen that screens like the FT813-5" or the FT813-7" from Riverdi behave erratically and sometimes disconnect the arduino MEGA from the PC. The original library for gameduino 23X is designed to take full advantage of AVR boards, but using selected screens for its low consumption.

The boards that have turned out to be the most stable so far are: teensy 3.6, teensy 4, teensy 4.1, black STM32F407VG, black F411CE, even the bluePill F103CB performed very well. In all of them it is convenient to power the backlight through an independent USB line, if possible, a USB-C adapter can be used, with the idea of ​​being able to use a USB cable of this type

MicroUSB to USB-C


NHD 7" on teensy 4.1


I can test with a teensy 3.2, which fails with a 4.3" FT813 NHD screen, when I connect the backlight to the teensy, I plan to spring a section of a microUSB cable and install a USB-C adapter, with the idea of ​​powering the backlight and teensy 3.2 with a single USB-C cable. As soon as I get the missing parts I share the result, I trust it will work based on the result with the 7" NHD screen.

Cross your fingers

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)

By the way, the voltage regulator of these AVR boards does not power the backlight of the screen, perhaps in 4.3" and 3.5" if possible, but from 5", the lack of power prevents the screen from working as it should .

It is necessary to power the backlight from a separate source, these screens can tolerate 5V on the TFT backlight.

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.

As I pointed out previously, the library for gameduino is not adapted to other screens, although it is true that it has the initialization structure that allows several MCU platforms to be used, it is necessary to add the specific parameters of each EVE-x screen. It can handle screens from the FT80x, FT81x and BT81x families (in this last series, the memory section managed by QSPI has not been explored). Compared with the official library for EVE-x in the arduino IDE, the library for gameduino is quite simple to use, and greatly reduces the learning curve.

We must add the timing table of the TFT in particular (Hsync, Vsync, Voffset, Hoffset, etc.), and some aspects related to the frequency of the SPI-1 bus and the frequency of the EVE-x chip.

These data come in the datasheet on the screen.

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.

It is relatively easy to add the code to export to a custom library for gameduino 23x. I attach the modified files and the steps that indicate where they should be copied into the Eve Screen Editor (ESE) folder.



The procedure works only for the ft81x family, however it's compatible with bt81x family, except for the instructions regarding flash memory


MCU: teensy 4.1
TFT: NHD FT813 5"
Wiring:
CS         --- 10
MISO     --- 12
MOSI     --- 11
SCK       --- 13
VCC       --- 3v3
GND      --- GND
BL-VCC  --- 5V
BL-GND --- GND


MCU: teensy 4.1
TFT: Riverdi BT817 5"
Wiring:
CS            --- 10
MISO        --- 12
MOSI        --- 11
SCK          --- 13
VCC          --- 3v3
GND         --- GND
PD/Reset   ---  24
BL-VCC     --- 5V
BL-GND    --- GND

In the case of the BT81x series it's necessary to connect the PD pin to a PWM pin (24), in order to create a reset during boot, otherwise the display chip will not initialize.