Display corruption?

All things relating to OLED Screen(s)
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Display corruption?

Post by G8SEZ » Fri Jul 20, 2018 12:04 pm

I have several Pi-Star devices running on RPi Zero Ws with an MMDVM_HS HAT board, the OLED displays are standard 128x64.

What I notice is that the larger text, scrolling "MMDVM" and static "DMR", often have various small corruptions with pixels either off when they should be on or with odd little lines of a few lit pixels extending vertically from the 'correct' lettering. This is OK after a reboot but gradually corrupts as the uptime increases.

Any idea if this is a hardware issue or is it subtle memory corruption within the MMDVMhost software?

Anyone else see this?

Brian G8SEZ

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Re: Display corruption?

Post by KC6N » Sat Oct 27, 2018 2:01 pm

I see various types of "corruption" with the 0.96 display (the one from HRO) but it seems to clear up after a while. I see DMR show up in mid screen with info above, below and in the middle of it. Do I have a setting wrong somewhere?

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Re: Display corruption?

Post by VK7HSE » 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

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Re: Display corruption?

Post by W3WDC » Sat Feb 16, 2019 2:25 am

I'm running V4.0.0-RC3 on a MMDVM v1.2 Duplex board on Pi 2B and am also seeing the OLED display corruption. Also saw it on V3.4.17 before I upgraded.

It's fine when no status words in the larger font are displayed: CW TX, Idle, Stopped, -CLOSE- When displayed those status are either pixilated or split in half. It's almost like the font is wrong or the wrong scale. When screen goes standby MMDVM logo goes to top and is displayed normal. When TG status display returns the DMR logo is displayed in the middle of the screen (should be top) with the TG status pushed to top and bottom. Occurs with scroll or no scroll.

Seems to work best with CW ID = 0 , which eliminates the need for CW TX and Idle to be displayed. The only time it goes corrupt is when -CLOSE- or Stopped is displayed. Otherwise "perfect" except I'm not sending a CW ID.

Changing Log | DisplayLevel (and FileLevel) to 0 doesn't change the behavior I'm seeing.

Running V4.0.0-RC3 on a Pi Zero W with MMDVM Simplex with OLED and no corruption there. Perfect displays with or without scroll.

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Re: Display corruption?

Post by G0OFY » Tue Jun 18, 2019 12:59 pm

Same problem on rpi2 B v1.1with a .96 screen. At switch on MMDVM shows at top of screen and at tx, info displays correctly. If cwtx is on that scrolls from left to right. When idle shows it starts to scroll right to left and the screen pixilates at random and scrolls. On the next tx DMR is showing plus the slot and tg info but it positioned anywhere on the screen.

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