ST7735_t3 Library - Colors Mismatched

[mgaert]

I'm running the graphicstest.ino example. If I change the color of the line

  testdrawtext("Lorem ipsum dolor sit amet, ...

to ST7735_RED it shows as blue. Most of the other colors are like this except ST7735_MAGENTA which seems correct. The display is a Sitronix ST7796S, "320RGB x 480 dot 262K Color with Frame Memory Single-Chip TFT Controller/Driver."

Thanks for any thoughts and help.
Michael

 

[jmarsh]

Magenta is equal parts red and blue so it would make sense that it appears normal if they are swapped...

 

[mgaert]

So some further details... black, white, green and magenta are correct. Blue, red, cyan and yellow are switched. If they were all switched I would assume it was a setting in the display or the library. But I'm missing something basic I think.

Thanks.

 

[mgaert]

Could this be about RGB vs BGR color order? There is a setting for that in the library but I’m not sure how to use it.

 

[mgaert]

Haven't been able to set the code to swap colors, seems to be doing BGR. There isn't a specific setting for that, although there are several references to MADCTL_BGR. My display doesn't have a 'tab' and even when I tried to 'break' the library by rewriting the

writedata_last(...

line here by swapping MADCTL_RGB and MADCTL_BGR a couple ways (original shown):

void ST7735_t3::setRotation(uint8_t m)
{
    //Serial.printf("Setting Rotation to %d\n", m);
    beginSPITransaction();
    writecommand(ST7735_MADCTL);
    rotation = m % 4; // can't be higher than 3
    switch (rotation) {
    case 0:
         if ((tabcolor == INITR_BLACKTAB) || (tabcolor == INITR_MINI160x80)) {
            writedata_last(MADCTL_MX | MADCTL_MY | MADCTL_RGB);
        } else {
            writedata_last(MADCTL_MX | MADCTL_MY | MADCTL_BGR);
        }
        _width  = _screenWidth;
        _height = _screenHeight;
        _xstart = _colstart;
        _ystart = _rowstart;
        break;
    ...

didn't work, no shocker really.

So, any thoughts about how to set this example to flip colors would be helpful.

Thanks.