7" Intelligent Series Aspect Ratio

1

Have just received a (genuine) Nextion Intelligent Series NX8048P070-011C (800x480, 7", capacitive) and am trying an existing app for a Nextion Advanced Series NX8048K050 (800x480, 5", resistive)

Loaded my LTS editor app into Editor 0.58, fixed an unrelated issue (seems that string variables cannot start with “$” in 0.58?), compiled OK, played with debug OK, copied .tft file to SD-Card and updated display via SD-Card - all OK.

First, easy, observation on the real screen is that my buttons with a .pic attribute set to a say 89x89 .png containing a circle, don’t look round - they are stretched horizontally.

On further investigation, 800 pixels x 480 pixels is an aspect ratio of 1.666, but the measured visible display area is ~154mm x ~85.2mm which is an aspect ratio of 1.807 - hence the horizontal stretching and the potential conclusion that the 7" Intelligent series doesn’t have square pixels. Which is a bit (a lot) of a problem when trying to draw/display circles…
…or in fact when trying to draw/display just about anything

In “debug mode” in Editor 0.58 everything is drawn round, as expected.

Any ideas please?

Regards
C

2

…or to put it simpler…why does

for(test.val=0;test.val<=480;test.val+=20)
{
  cir 400,240,test.val,RED
}

produce a set of concentric “circles” that aren’t round i.e. elongated in the x-direction?

Seems a bit of a serious problem to me?

Regards
C

3

This problem is not specifically related to Nextion. Although the symptoms make it harder to develop for this screen. I would assume this sort of specs would be mentioned in the technical specs of the device…
.
Not sure if these are actually the same TFT panels that were used, but there is some sort of theme with 7" panels:

So, the only thing you can do is stretch all graphics so they look the way the intended…:unamused:

4

fvanroie

Thank you for that additional information.

Yes I suppose the information is in the specs - but you have to spot that you need to divide the visual area xy dimensions (in mm) and compare the answer to the division of the xy pixel dimensions to see that the pixels aren’t square.

The same “problem” appears to exist for the 10" display - so maybe I was just lucky when I picked the Enhanced 5" display for my app, where the pixels are essentially “square”, and round .png circles are displayed as round etc

For my app, non square pixels is probably a deal breaker. A Big Shame.

I would hope/guess that Nextion will release smaller than 7" Intelligent displays in the future with square pixels…
…but as someone in the Pi thread says, it’s pretty unbelievable that the display hardware designers created non-square pixels, with their obvious significant problems in some/most scenarios :frowning:

Regards
C

5

I can confirm this is the case on the Nextion 7" Enhanced screen as well. I have stretched my graphics but there’s no easy way to do the same for fonts so they’re all a bit fat. :frowning:

6

Hi iref

I have them same problem, I have to do this with 200 pictures.
How much did you have to stretch in numbers / % if you can remember?

Regards
Peer

7

The actual aspect ratio is around 1.8. So one method is like this:

  1. Make your images 864 x 480 (that’s a 1.8 aspect ratio)
  2. Scale them down to 800 x 480

If you have 200 pictures then you should use ImageMagick’s mogrify tool. One command will do them all at once.

1 Like
8

Thanks for the reply, I will jump into this scale project :o)

9

Thanks for this tip!

For smaller images, I’m multiplying it with 1,076 to scale this only up in the 480 direction.
So 400x400 will be 400x430 or 430x400, this depends on the direction of the screen.