Raspberry Pi 3.5" Display Woes - Page 1
Forum section: electronics / beginners

author: metrologist
author_rank: Super Contributor
timestamp: May 15, 2024, 12:15:14 am
content: I finally got my Pi set up with latest OS and WSJT-X and wanted to use a 3.5 LCD display. I bought the hosyond.com display from Amazon and used their code to install the drivers:http://www.lcdwiki.com/3.5inch_RPi_Displaysudo rm -rf LCD-showgit clonehttps://github.com/goodtft/LCD-show.gitchmod -R 755 LCD-showcd LCD-show/sudo ./LCD35-showThat seemed to go well and it rebooted, but only to a blank screen with an underscore or hyphen at the upper left corner.That's it.Is there something I don't know, like I have to use a specific OS or is this LCD and code above just trap?

author: RoGeorge
author_rank: Super Contributor
timestamp: May 15, 2024, 06:35:29 am
content: Sometimes cheap LCD clones may look the same, yet they may use another chipset inside the LCD. Are you sure your LCD is the right model for the driver you are installing, LCD35-show?If yes, try an an older OS not the newest. RPi foundations calls previous Raspberry OS "Legacy" version. Current OS is based on Debian Bookworm, previous was based on Debian Bullseye.I would try that because there were some recent changes in the Linux kernel, changes that might be incompatible with older drivers. I would even try the OS before Legacy (based on Debian Buster, you'll have to manually download the card image from the Raspberry archives), but only if Bullseye doesn't work. Then I'll start looking for another LCD driver.Of course, you can connect the RPi to your LAN, and SSH to it from another desktop or laptop. SSH must be enabled to work, there is an option to enable it at install time. Once you SSH into RPi, you should be able to get a command prompt and investigate the logs for errors, though that might take a lot of time. It would be much faster and easier to just try an older OS version, or try another driver.Install whatever else you need (like ham tools) only after you have a clean OS image working with the LCD. If you already have many customizations made on the currently bricked OS and don't want to lose them, backup the entire card (dd), or at least backup your home directory (including the hidden files, where most of the installed program are saving their settings).

author: metrologist
author_rank: Super Contributor
timestamp: May 15, 2024, 10:26:32 am
content: OK, reading the Amazon reviews, said it does not work with Bookworm but does work with Bullseye.I was trying to use the SD Card Copier and that got stuck for hours, and now my spare SD card looks like it's toast - that was the only name brand Sony card I had, rest are off brands.Not sure if I'll be able to get WSJT-X to work on Bullseye, will find out.

author: RoGeorge
author_rank: Super Contributor
timestamp: May 15, 2024, 10:45:57 am
content: Why do you think WSJT-X wouldn't work, does the readme file specifies it wouldn't work with Bullseye? If not, of course it will work. Bullseye was only a few months ago, it is still maintained, has updates and everything. It's the stable thing. Bookworm is the one less trusty, should be seen as experimental for another year or so.Unless you are a programmer hunting for bugs, never go for fashion and the most recent OS, go for the most stable and do not upgrade until your OS becomes unsupported. The newest a software is, the slower it will work, and the more unpleasant bugs may have. Use the oldest software, because in all that time since it was released, others reported bugs and the developers have had the time to fix them.A card should not be possible to be destroyed in an hour. Most probably something else happened. Refer to the exact program, exact reader the card was plugged in, and the OS and tool you used for backup (or whatever operation was tried).I use Linux, and dd the card images myself. So far didn't damaged any card. After you dd the card, the saved image can be mounted as a loop device in any Linux distro, and you can read files from the saved image in case you need something from there.

author: metrologist
author_rank: Super Contributor
timestamp: May 15, 2024, 12:09:00 pm
content: For the SD card, I was using Bookworm > Accessories > SD Card Copier. It got stuck for hours writing the second partition.I made a clean install of Bullseye 64b and installed the LCD - and it works...Now the problem is the windows run off the display.WSJT-X installed but is not usable because most of the window is off the screen.In Preferences, I changed the resolution to 640x480, the minimum, and that helped a little, but display is 320x480.I tried some things likexrandr -qThen setup the panning itself :xrandr --output DISPLAYNAME --mode 640x480 --panning 1920x1080But xrandr does not tell me the display name so cant use step 2.Then I tried to edit /boot/config.txt values tooverscan_left=24overscan_right=24Overscan_top=10Overscan_bottom=24Framebuffer_width=480Framebuffer_height=320Sdtv_mode=2Sdtv_aspect=2and that made it worse again.