Display corruption?

All things relating to OLED Screen(s)
KE0AEQ
Posts: 1
Joined: Mon Aug 05, 2019 11:11 pm

Re: Display corruption?

Post by KE0AEQ »

Hi, I hope I am one of those that can find this thread handy, but I can open a new thread if it is appropriate. My friend and I have Jumbospots on Pi Zero W"s that work great. He decided to buy 2 duplex hats to put on a Pi 3B. We have tried numerous settings in the configuration, but cannot get the display to light up, even for a second, with the duplex hats attached to a Pi 3B or a Pi 2. Nor will they boot (no dashboard shows up). When attached to a Pi Zero W, they will boot, dashboard shows up, and we can access Brandmeister, in this case. But the display is always blank. We were thinking it was bad hardware (the first one he got had a cracked display, so the vendor sent him another one). Saw this thread and thought there might be some help here. I don't "code", and use Linux only for dualbooting my computers and a few other things. Thanks in advance.
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G0WBX
Posts: 15
Joined: Wed Sep 23, 2020 8:01 pm

Re: Display corruption?

Post by G0WBX »

Hi.

Further to my general issues getting the Pi-Star to send audio to the network (pending.) I have at least found a fix for "My" 0.96" OLED display corruption.

This is when using one of the cheap common as muck 0.96" OLED displays that litter the interweb auction sites. The one (in my case) has Vcc and Gnd reversed too (needing some work with fine enamel wire to sort out, after pulling those pins from it.)

After a lot of searching, I found this site:- https://wp.hamoperator.com/?p=1121 Seems these dirt cheap displays use an older driver chip, and also have a subtly different display RAM layout. Hence the mayhem with the text display.

The information there, and the modified driver it points to, seem good, in as much as my display is now fine.

Thanks to K9EQ (the site owner I think) and whoever "Charles" is for the work on the driver to accommodate the older display chip.

But, though the idle scrolling logo screen saver works, if that is enabled, normal text display doesn't work (it remains garbled.)
I had to disable both scrolling, and showing the logo at idle.

Now, when the hotspot is active, the correct info is displayed, and is stable. Even better, after a period of inactivity, the display is blanked (goes dark) a default screen saver.

Note though... I expect that modified driver to be over-written during any later OS/System update to the Pi-Star, so you'll have to re-apply it again. I have kept the original file renamed as a backup, + a similarly archived copy of this alternative driver library to make things easier when re-patching is needed.

73.
Dave G0WBX/G8KBV
Forever confused.
N5BOC
Posts: 5
Joined: Sat Apr 14, 2018 5:49 am

Re: Display corruption?

Post by N5BOC »

VK7HSE wrote: Tue Oct 30, 2018 11:17 am Ensure that you have the display logging set to zero (0) as that's what is the cause for the visual corruption

This is in the expert panel under mmdvmhost Image

Sent from my Pixel 2 XL using Tapatalk
This saved my BACON. Thanks so much VK7HSE
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