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bobthebuilder
Newbie

Joined: 07/03/2022
Location: Australia
Posts: 3

Posted: 03:46am 23 Jul 2022

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I recently bought an Explore64 and designed a carrier PCB so that it can piggy-back onto a 5" SSD1963-based panel.

I previously bought a Rictec Explore100 kit, also piggy-backed onto a 5" panel.

For testing, I bought 4 panels from 4 different vendors on Ebay.

The software I wrote starts:

CLS

(global variables defined here)

GUI SETUP 1
GUI DISPLAYBOX 1, 0, 0, 236, 146
GUI DISPLAYBOX 2, 240, 0, 236, 146
GUI DISPLAYBOX 3, 0, 150, 236, 146
... etc

So, a series of DISPLAYBOXES to be filled with text - all standard stuff.

My code runs perfectly with two of the panels, on the Exp64 and the Exp100.

With the other two panels, the top borders of the top boxes do not display, and vertical lines show a +/- 2 pixel horizontal jitter. The same effect occurs on both the Exp64 and Exp100.

I found a workaround. Do not write to pixel X=0 or Y=0. The code is:

GUI DISPLAYBOX 1, 1, 1, 236, 146
GUI DISPLAYBOX 2, 240, 1, 236, 146
and so on.

This gives a perfect display on all panels.

I'm happy with the workaround, but Geoff and Peter might like to check the MMBasic source code for an explanation. It's weird that only some panels are affected.

Cheers, BtheB.

Bowden_P
Senior Member

Joined: 20/03/2019
Location: United Kingdom
Posts: 162

Posted: 02:51pm 23 Jul 2022

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Hi bobthebuilder,
Just wondering if the OPTION LCDPANEL alternatives have any bearing on the effect you are seeing?
i.e.
"OPTION LCDPANEL SSD1963_5" or "OPTION LCDPANEL SSD1963_5A"

While I have not seen any differences myself, there can be timing issues with some panels, hence Peter's 2 "OPTION"'s here.

With Regards, Paul.
Edited 2022-07-24 00:52 by Bowden_P

Nothing so constant as change.

bobthebuilder
Newbie

Joined: 07/03/2022
Location: Australia
Posts: 3

Posted: 12:18am 25 Jul 2022

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Hi Paul,
Tried _5A early on, gives no pix on either LCD panel.
B

Grogster

Admin Group

Joined: 31/12/2012
Location: New Zealand
Posts: 9757

Posted: 05:33am 25 Jul 2022

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Welcome to the forums.

That's interesting. I will see if I can dig out my bench-testing E100+5" LCD setup and run those tests. What version of the MMBASIC firmware are you using?

I do recall there being issues in the past with SOME 5" LCD panels. One fix I remember the members here discovering, was to solder a good thick and solid ground between the LCD panel and the E100 board, and not rely solely on the single GND connection pin on the display, as the current drawn by the LCD would sometimes create a voltage-drop effect on the ground pin if there was any hint of resistance there, and that could cause issues. I know that definitely fixed the issues some members were having with 5" panels at the time, so you could try that, BUT the very fact that changing the X/Y co-ordinates from 0,0 to 1,1 fixes it for you, suggests there is not a voltage-drop issue, and it is indeed a curious situation and fix.

Smoke makes things work. When the smoke gets out, it stops!

bobthebuilder
Newbie

Joined: 07/03/2022
Location: Australia
Posts: 3

Posted: 02:38am 26 Jul 2022

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Paul, Ver 5.0501 for both panels.
B

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