7-inch monitor for Le Potato with readable startup text

Hardware
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1

I’m fairly new to Linux and this is my first experience with an SBC. I have a Le Potato running Ubuntu 22.04.4 LTS with Octoprint for my Ender 3 v2. I followed this guide to get it running:

It seems to work except for the web cam, which I may be asking about later.

In the meantime, I purchased this 7-inch monitor to use with the Le Potato:
https://www.amazon.com/dp/B09ZD8YS7L
When I boot up, output is displayed, but it is very small and nearly unreadable.
It is connected via HDMI. The listed resolution of the screen is 1024 x 600. Is there some setting or file that I can change to make the text bigger or clearer?

Another post mentioned the xrandr command, but that only returns the message, “Can’t open display.” I see one other message on local login that may be related, “usb 1-1.1: 3:1: cannot get freq at ep 0x84.” I don’t see that message when I login via PuTTY.

A review of a similar screen says to, “edit the resolution settings in your /boot/cmdline file to be 800x480 or lower and it works great.” Is there a way to do that with Ubuntu and the Le Potato? If not, is there a different 7" monitor that would work better?

2

The monitor has a broken EDID. It does not set the preferred resolution. Either dump and patch the EDID and force Linux to use the custom EDID. Your other choice is to buy a monitor that works properly.

For the webcam, make sure you have enough power.

2 Likes
3

Thank you! Is there a preferred 7" monitor or brand? Or at least one that has been used successfully? I am still in the return window for this one and will gladly return it.

Thanks for the webcam tip, too. I posted that issue in at OctoPrint and my URLs may be wrong from that guide. I haven’t tried that solution yet.

I believe that I am using the recommended power supply:
https://www.amazon.com/GenBasic-Indicator-MicroUSB-Raspberry-Computer/dp/B0C8V23K7Z
Is there a way to test the power?

Thanks again!

4

If there isn’t a preferred monitor or brand of that size, are there specs or capabilities I can look for when choosing a small monitor to minimize the possibility that the next one I choose has the same problem?

Thanks

5

We recommend this 7" Touch Screen Monitor.