Screen ghosting after welcome screen

[gfwilliams]

Posted at 2023-03-21 by @gfwilliams

Is it me, or if you leave the Bangle right at the end of the welcome screen (so just start it and leave it) for a few minutes, there's really bad ghosting afterwards?

I just noticed it on a watch here - I'd never really seen it that bad before, but maybe it's something about the welcome app (not sure what!).

[espruino-discuss2]

Posted at 2023-03-21 by @thyttan

I get it too, very noticeable after loading BW Clock right after exiting the welcome app. But pretty quickly, 10 to 30 seconds, the ghosting is much milder or even gone.

I tried this with the torch app as well and got similar ghosting when switching back to BW Clock, except for where the red software back button had been on the torch app.

Device Type BANGLEJS2
Firmware Version 2v17.1

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Posted at 2023-03-22 by @gfwilliams

Thanks - do you notice it anywhere else?

I'm wondering what we do in https://github.com/espruino/BangleApps/blob/master/apps/welcome/app-bangle2.js that makes it so apparent in the welcome app.

I'll do some testing with:

Bangle.setLCDTimeout(0);
Bangle.setLocked(0);
Bangle.setLCDPower(1);

As I think that may be causing the problem...

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Posted at 2023-03-22 by @gfwilliams

Just fixed it!

So hopefully no more ghosting issues when the LCD power is forced on at boot time.

It's just a pain it happened with the app that starts when everyone first gets their watch! I know one person recently returned their watch because they didn't like the ghosting in the welcome screen (and I guess they never bothered to explore other apps).

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Posted at 2023-03-22 by @thyttan

Thanks - do you notice it anywhere else?

I know I've noticed ghosting in different places at times, but I don't recall specifics now.

Just fixed it!

Nicely done! Seems to have fixed the ghosting after using the torch app as well, as far as I can tell.

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Posted at 2023-03-23 by gfric

I have the ghosting when switching from teatimer to glbasic clock sometimes. Teatimer only quits by long pressing the button. I think it's a teatimer issue. ;)

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Posted at 2023-03-24 by @gfwilliams

Seems to have fixed the ghosting after using the torch app as well

Ahh - I imagine that was very similar then (forcing Bangle.setLCDPower(1); on)

@gfric you mean with an older firmware? I bet this once fixes it

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Posted at 2023-04-01 by 23Ro

Found this thread when searching for the ghosting issue.
Just started using my new v2 two days ago (long time v1 user), and oh boy, ghosting is everywhere for me.

I use the Dev Clock, and when I open the menu, it is hard to read some of the Text next to the icons.

I'm working on some of my apps right now, and when navigating from menu to menu, I notice the same issue. Is there anything I can do to make this less noticable? Currently I don't enforce any additional refresh/handling of LCD states.

Edit: Might be worth mentioning: it is much more noticable in dark mode

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Posted at 2023-04-01 by @thyttan

Maybe it would be helpful if you shared a backup of your watch along with steps to reproduce the situation where you get ghosting in menus?

Like I said before, I've noticed ghostig sometimes at different situations. But I don't see it frequently and don't remember specifics.

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Posted at 2023-04-03 by @gfwilliams

... and please can you try upgrading your Bangle.js firmware to the latest 'cutting edge' firmware? That may will help you out significantly.

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Posted at 2023-04-19 by @thyttan

I just had to install the firmware with the DFU android app to my Bangle 2. When it finished and the watch loaded BW Clock lite there was noticeable ghosting. Just a FYI.

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Posted at 2023-04-20 by @gfwilliams

Thanks - from the DFU app? Yes, that one would be expected since we don't go to a lot of effort in DFU to keep refreshing

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Posted at 2023-05-03 by ga

I have ghosting of the welcome screen too.
Not sure if this is related: I also have problems with the screen not being cleared with clearRect.
On the image, the second line from top should only have two seperated dots.
In the bottom, the vertical lines are 15 px, the ckearRect is 36px so there should nit be any residues.
The screen is only redrawn every 3 hours in that part. The top part is redrawn every 30 minutes.
Probably a different issue though, I assume the ghosting is an electrical thing and I think at least on my device there is too much mechanical stress and tension on the screen, there is some uneven lighting that looks like the screen is pressed against the parts under the screen. I could not make a photo of this, is there a large IC or similar in the lower part under the screen? and a small ~3by3 mm square thing in the bottom left corner?
The grafic residues in my app look more like a software problem though.

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Attachments:

• 20230503_045620.jpg

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Posted at 2023-05-04 by ga

heres a photo, exaggerated

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Attachments:

• screenexaggerated.jpg

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Posted at 2023-05-04 by @gfwilliams

Hi - I don't think your clearRect issue is related - maybe make a new post for that if you can narrow it down to a simple code example that reproduces it? But personally I'd think that one is likely a bug in your code somewhere.

In terms of ghosting on your screen, I believe they all do that. Can you see anything with the backlight off?

I don't believe it is mechanical stress or anything to worry about - the backlight consists of two LEDs shining sideways onto the screen - when the backlight is on you see this slightly odd pattern because of how the light shines out. It's a side effect of it being a transflective screen - I believe they have to front-light it, which means they can't have that layer that spreads the light out that you would have on a normal LCD.