question

mauri avatar image
mauri asked

Cerbo GX screen setup

I'm trying to get the generic HDMI 7" touch screen to work with Cerbo GX.

- Screen resolution is 1024x600.

- Touch output is via USB, not via HDMI.

Just plugging the display in, the USB not to the closest to HDMI port, the display works very close to perfect, even the touch input works somehow. (Just need calibration I think)

Below is the display when plugged in to the already running Cerbo:

20210224-080018.jpg

When the Cerbo is booted with display plugged in, something different happens, the height seems to be wrong:

20210224-080255.jpg

There are just two problems now:

- The display resolution when Cerbo booted when connected to the display, as seen in the pic above.

- The touch input works, but the touch point is way off. (Lower that the actual touch points, but work for example for switching between tile and overall views.)

So by just plugging in, this setup could already work as semi-dummy display... But of course this is not good enough, and there I need some help from the community.. ;)

Can anyone advice how to change settings for the external screen for Cerbo, and how to do the screen calibration?

I found lot's of information about setups, but mostly related to Raspberry Pi, not to Cerbo hardware, for example here, or at least I could not apply those to Cerbo yet.

I can edit files and execute commands in Cerbo by SSH with root access, found files like "start-gui.sh" (related to remote console?) and "pointercal" which seems to be somehow related to issue, no solutions yet by that way.

More or less same question was earlier here, but could not find the answer via that. (I guess I need more Cerbo specific information because I'm not able to apply Raspberry related advices yet to this case.)


cerbo gx
20210224-080018.jpg (695.1 KiB)
20210224-080255.jpg (614.1 KiB)
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2 Answers
Kevin Windrem avatar image
Kevin Windrem answered ·

Don't know if you've seen this but it has info about touchscreen calibration.

https://community.victronenergy.com/questions/65414/venus-os-raspberry-4-5-mpi5001-calibration-touchsc.html

IIRC, the calibration worked on an HDMI display I played with a few months ago. That was on the RPI but it might work on Cerbo


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mauri avatar image mauri commented ·

Thank you Kevin

Can anyone advice how this can be applied on Cerbo GX hardware?

I was searching the forum, and there are Pi related solutions, but the problem is that I can't apply them to Cerbo. For example the file "config.txt" seems not to be present in Cerbo. Or is it that I just can't locate it? (I ran search for whole filesystem for this file without success.)

Thanks in advance

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Kevin Windrem avatar image Kevin Windrem mauri commented ·

config.txt is the way the Pi does it's basic display configuration. Cerbo uses a different mechanism but I don't know what that is. If your screen is working properly without attempting to force a screen resolution, etc. then I wouldn't dwell on those things set up in config.txt

Regarding touch screen calibration:

You'll need to "go headless" to run the touch calibration. Simply enter touch /etc/venus/headless and reboot.

I followed the instructions in the page I linked previously starting with "then install tslib". I got the TSLIB calibration utility on my CCGX display but of course don't have a touch screen so couldn't go any further.

After you run the calibration:

rm /etc/venus/headless

Hopefully, you touchscreen will then track. Good luck.


BTW, you'll need to rerun the calibration after a software update because the calibration file is stored in /etc is overwritten by the update.

I have a script that manages stuff like this that if you can dabble in unix shell scripts it might help:

https://github.com/kwindrem/RpiGpioSetup

Obviously, my script would need modification to work with Cerbo.


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mauri avatar image mauri Kevin Windrem commented ·

Thank you!!

This was exactly that kind of "for dummies" guidance what I needed.

Now I managed to run the ts_calibrate on Cerbo:

20210226-082329.jpg

Only little problem that lower corner crosshairs were out of screen, but still managed to get Cerbo UI usable just by touching close to corners where I think that those crosshairs should appear.

Maybe this have something to do with the fact that ts_calibrate shows wrong screen resolution?

ts-calibrate.jpg

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ts-calibrate.jpg (48.7 KiB)
Kevin Windrem avatar image Kevin Windrem mauri commented ·

Yes, it's probably due to the fact that the Cerbo frame buffer doesn't match your screen. Maybe ask again on the forum for someone that can explain how the screen resolution is set in Cerbo

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mauri avatar image mauri Kevin Windrem commented ·

Thank you!!

Works perfectly now, just used:

fbset -xres 1024 -yres 600


It was great time to get this working, tomorrow the Cerbo is goint to it's off-grid location (without screen just now) so it was good to find solution to this issue now, screen will be installed later, it's good to know in advance how the setup is done. Luckily there is information available to make changes more permanent.

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tilapia avatar image
tilapia answered ·

Mauri,

I have the same issue, I am trying to connect a generic touchscreen monitor to the Cerbo GX. How do I edit files and execute commands in Cerbo by SSH with root access????? I connected to local devices and VRM. Some parts of the touchscreen react, but not much. HDMI and USB C connected to touchscreen. Help.

Dave/lagoon 39

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