Screen aspect ratio fix

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wabbastang
Posts: 6
Joined: Fri Nov 15, 2019 5:37 pm

Screen aspect ratio fix

Post by wabbastang » Wed Jan 15, 2020 11:52 am

When I first started using my BB controller, I had it plugged into a widescreen monitor via HDMI of course. I recently switched it to a standard old 19" LCD, but the video output remains in widescreen. Restarted, dug through settings. Seems like a silly problem but I can't figure out how to fix it, and makes the screen extra-short which I'm constantly having to scroll around.
20200115_115005.jpg

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Doug
Posts: 343
Joined: Fri Feb 02, 2018 4:56 pm

Re: Screen aspect ratio fix

Post by Doug » Fri Jan 17, 2020 9:31 am

Thank you for pointing this out. I have been running into the same problem. I have opened a github ticket on the problem. You can follow the progress on that ticket on github at:

https://github.com/buildbotics/bbctrl-f ... issues/240

wabbastang
Posts: 6
Joined: Fri Nov 15, 2019 5:37 pm

Re: Screen aspect ratio fix

Post by wabbastang » Mon Jan 20, 2020 5:31 pm

This should still be addressed, but just in case anyone else has this same issue after changing monitors, I fixed it and here's how.

I found that config.txt was specifying the screen resolution. Normally on a Pi this is not declared, but there must be something in the BB firmware that does it upon first started. The biggest problem is that the file system on these is read-only (a good thing as Pis have a tendency to corrupt file systems when not properly shut down), so you have to mount it as rewriteable, edit the file, and then put it back to read only. Step by step:

SSH into your Buildbotics: Via Windows, Putty is the common SSH terminal. Connect to your unit's IP address and log in. Default credentials are listed in the manual as bbmc/buildbotics

All the commands must be prefaced with "sudo" to run them as root since the bbmc account apparently is not. Run the following, ignore inside the brackets:
sudo mount -o remount,rw /boot [makes the file system writable]
sudo nano /boot/config.txt [edit the config file]

Scroll down about a page and you'll find something similar to this:
framebuffer_width=1280
framebuffer_height=720

Change the values to your screen resolution. Ctrl^o to save, confirm changes with Y and then Ctrl^x to exit the editor.

sudo mount -o remount,ro /boot [mounts file system as read only]
sudo reboot [resets the machine]

Full screen at last!

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Doug
Posts: 343
Joined: Fri Feb 02, 2018 4:56 pm

Re: Screen aspect ratio fix

Post by Doug » Tue Jan 21, 2020 2:28 pm

Thank you for the help. I went in and modified config.txt as you suggested and after quite a bit of trial and error, I was able to come up with a pretty good combination for a Chinese touch screen monitor that I bought.

As you say, this still needs work, but your suggestion makes a good work around until we can give it some more attention.

I will update the github issue with a reference to your posting.

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