Need to see more content on your 7in Touch display?

[aBUGSworstnightmare]

Decided to get an official 7in touch display but instantly figured out that 800x480pixel resolution is a little too low for most of my use cases (my custom 7in is 1280x800pixels: viewtopic.php?f=44&t=158525&hilit=nexus+N2).

Don't know if this has been posted already but you can simple get to see some more content on the official display by changing the frame buffer size in config.txt
I think that 1024x614 pixel is a good trade off between quality and achievable resolution (see screen capture below).

https://drive.google.com/file/d/0B5lt0B ... sp=sharing

Simply

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cd /boot
sudo nano config.txt

and change frame buffer lines to

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...
# uncomment to force a console size. By default it will be display's size minus
# overscan.
framebuffer_width=1024
framebuffer_height=614
...

reboot and check resolution with

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fbset -s

[buja]

Thanks for sharing this, easy method and works perfectly. Things get a bit too small for my taste, but that's just my eyes getting older I guess

[W. H. Heydt]

Thanks for sharing this, easy method and works perfectly. Things get a bit too small for my taste, but that's just my eyes getting older I guess

Yeah...that's the problem I run into. It's why I wish that one of the early ideas WRT RPF displays would happen...having a 10" follow-on device.

[mikronauts]

Also has aliasing issues when scaling down to the native panel resolution.

I have a cheap Win10 tablet with a 1024x600 display - but MS forces the mode to 1280x800, so everything is scaled & fuzzy.

[stefanv]

That "screen" capture isn't really representative, because it shows what's in the frame buffer (1024x614 pixels), not what is actually displayed (1024x614 pixels squished into 800x480 pixels). I.e., it's not really a screen capture, but a frame buffer capture.

However, I could see this technique being used to deal with the display's non-square native pixel issue if you were using it for watching videos instead of working with Linux.

Question: Does the touch screen still line up with the image when you use this larger frame buffer?

[aBUGSworstnightmare]

That "screen" capture isn't really representative, because it shows what's in the frame buffer (1024x614 pixels), not what is actually displayed (1024x614 pixels squished into 800x480 pixels). I.e., it's not really a screen capture, but a frame buffer capture.

However, I could see this technique being used to deal with the display's non-square native pixel issue if you were using it for watching videos instead of working with Linux.

Question: Does the touch screen still line up with the image when you use this larger frame buffer?

Yes, you're right it's a Frame buffer copy, but still usefull to compare what you should see and what is displayed in real life when doing this.
If you have a Screen on Hands you can test it and compare by yourself.

The touch knows nothing about a changed Screen Resolution. It's still useable with a pen, but not very accurate in case of small touch Icons. Nevertheless, OS Buttons are still useable.

[stefanv]

The touch knows nothing about a changed Screen Resolution. It's still useable with a pen, but not
very accurate in case of small touch Icons. Nevertheless, OS Buttons are still useable.

It's more a case of whether X deals properly with the mismatch between the touch resolution and screen resolution. I tried it, and see that it does.

Unfortunately, my idea of using your technique to work around the non-square pixels doesn't work. If you choose a resolution that isn't the same aspect ratio as 800x480, you end up with black bars on the top and bottom or left and right, instead of the image stretching to fill the screen. Oh well.

[LennartH]

Hey guys,

yes, you can use the method to scale the display to remove the non-square pixel effect.
I decribed it in this thread.

Cheers.

[Baldy42]

Which version of Raspbian and Pi are you using to get this to work?
I’ve been trying everything on my Pi2 with the latest Raspbian Stretch and nothing works.
I have made sure that the /boot/config.txt is indeed changed and saved, yet I get no results upon reboot. Even trying to rotate the screen 90 degrees doesn’t work. Other settings (like overclocking) do work, but the only video setting that seems to make a difference is overscan.

[ab1jx]

OK, it seems to sort of work. My touchscreen is off to the point that selecting things from menus is off, that might be fixable with recalibration.

x11-touchscreen-calibrator is what I was thinking of. I have an Adafruit 320x240 display which never worked very well, but using that is how you calibrated the x11 part as part of the installation. There was something else for the console mode I think, you did that first.

My question is what's the hardware resolution? If you look at the spec sheet for the raw display from the original manufacturer what's the resolution? LCDs aren't like CRTs where you can fudge the timing a little and end up with a different resolution. A display has a certain number of physical pixels and if you aren't at that exact value it doesn't look right. People fairly often use a lower resolution but higher doesn't make sense.

[A11en]

I have tried this and it fixes the resolution issue but my mouse is offset a couple of pixels to the right and bottom , the touch works fine tho

Is there any way to fix the mouse issue I'm having

[ab1jx]

I have tried this and it fixes the resolution issue but my mouse is offset a couple of pixels to the right and bottom , the touch works fine tho

Is there any way to fix the mouse issue I'm having

It sounds like a calibration issue maybe only on a different device. Your mouse won't reach an edge of the screen? See viewtopic.php?f=108&t=205569&p=1278184#p1278184 but you'll have to look around to figure out where to put the calibration data at the end. Assuming you have libinput probably /usr/share/X11/xorg.conf.d/40-libinput.conf in the "libinput pointer catchall" section.

The calibration maxtrix method has a scaling section and and offset section. If your couple pixels is constant everywhere on the screen that would be offset. If it increases as you go from upper left to lower right that would be scaling. It's like the linear equation Y = mx + b. b is offset, m is scaling.

But make sure your kernel level stuff (evdev, evtest) is right before you mess with libinput.