ST7789 (V2)

[richcj10]

I have a display that states its a ST7789V2. It works well with the library from Adafruit. But has color problems with TFT_eSPI as well as the the display image is shifted up. (with unused pixels at the bottom)

I have been looking at making modifications to the x/y size and position to the display. But making changes in Rotation.h (ST7789_2) doesn't seem to effect the outcome. Something else seems to be overwriting the changes. Any other locations I need to look at?

[Bodmer]

#define CGRAM_OFFSET
Needs to be defined somewhere for the offsets to be used. See here for known display variants.

Example rotaion offsets are invoked here.

Not sure if all these have been copied to the _2 code variant.

You may need to call setRotation after tft.init() so the offsets get applied.

[richcj10]

That is what I am doing now. seems to keep with the same issue. I have a logic analyzer. I am going to probe the data line and see where the depart in config happens.

[Bodmer]

The colour problems are typically red and blue swap or inversion (blak = white and vice versa). There are setup options to correct these as they vary between suppliers.

Ofsets are determined in setRotation and applied for each graphics operation, see here.

What pixel pixel count w and h does your display have? Do you know what offsets are needed?

Post a copy of you setup as a zip file, there may be options you have not noticed.

There is a setViewport() command that can move the display origin and define a window size anywhere in the native display area so this is an alternative approach to dealing with offsets.

The variables colstart etc are private so cannot be accessed from a sketch. But they could be moved to the public zone and then accessed from a sketch. ie Serial.println(tft.colstart);

[richcj10]

280x240.
Setup71_ESP32_S2_ST7789.zip

[Bodmer]

For non-native widths and heights it is expected that this is defined in the setup, otherwise defaults may be used (240x320). So adding this will prevent over-ride:
#define TFT_WIDTH 240
#define TFT_HEIGHT 280

[richcj10]

Where should that be placed? I tried that in user configuration. Didn't move it.

[Bodmer]

In the setup file with pin definitions etc.

[richcj10]

Setup71_ESP32_S2_ST7789.zip
This is the video showing what the above config does. https://youtube.com/shorts/ITtnvjG3ok4

The display w/ Adafruit code looks just like this: https://www.adafruit.com/product/5206

[Bodmer]

I have added these lines to the init file for that display driver. This should make the offsets work.

It appears the display is inverted too. It is not clear if red and blue are swapped too. Add uncommented defines to your setup as appropriate to correct this:

// #define TFT_INVERSION_ON
// #define TFT_INVERSION_OFF

//  #define TFT_RGB_ORDER TFT_RGB  // Colour order Red-Green-Blue
//  #define TFT_RGB_ORDER TFT_BGR  // Colour order Blue-Green-Red

[richcj10]

Colors, Fixed :)

Display position, not yet. :( Same as before.

I hope to use the logic analyzer on the display tomorrow. I had to leave it at work.

[richcj10]

Changing the init line to this:

TFT_eSPI tft = TFT_eSPI(300,240);

Gave me assess to the entire display. Tho there still is an offset issue.

tft.setCursor(30, 20, 2);
// // large block of text
tft.setTextColor(TFT_WHITE,TFT_BLACK); tft.setTextSize(1);
// We can now plot text on screen using the "print" class
tft.println("Hello World!");

Puts the H right at the Left most of the display. (Instead of 0,20)

Changing values in ST7789_Rotation.h doesn't affect the displays position.

[richcj10]

Thanks, I will Play with this tonight. Your support has been great.

[Bodmer]

I have updated the master library to add the required offsets to the ST7789_2_DRIVER. They were only in the ST7789_DRIVER files.

[richcj10]

Do you have a tip jar? AKA buy you a coffee?

[Bodmer]

No, thank you, just give a donation to a charity of your choice instead.

[elgerg]

@Bodmer are you an angel?