Daylight readable display

Other Hardware Displays
1

I originally had a 20x4 green backlit with black character lcd display. In daylight I could not see the backlight but the display was readable. I need more information on the display so I was thinking of switching to 128x64 green backlit with black character GLCD display. But have found other alternative, Chinese 2.8 inch TFT LCD display costing just 150 INR($2) more.
Chinese 2.8 TFT display

.trashed-1740384802-Screenshot_2025-01-25-13-42-45-099_com.android.chrome
.trashed-1740384802-Screenshot_2025-01-25-13-42-45-099_com.android.chrome1080×2460 111 KB

My concern is are these display readable in sunlight? A picture available in another post (by another user) shows how the 20x4 display was readable in sunlight

LCD 20x4
LCD 20x41024×768 111 KB

2

TFTs and OLEDs are more or less invisible outdoors when its sunny. TFTs are sometimes called LCDs, when clearly they are not. The red display you showed is a TFT, assume its invisible in sunlight.

The 20x4 display you showed is a transflective LCD, highly visible even in direct sunlight. Standard LCDs are not so good in sunlight.

For a graphic display that is also visible in direct sunlight there is the OpenSmart LCDs, 128x64, graphics and character libraries available.

There is a 2.0" and an 1.8" OpenSmart.

The smaller 1.8" one has a switchable backlight so is visible in poor light or the dark as well.

2 Likes
3

I think TFT are a type of LCD because they use similar liquid-crystal technology. But they are constructed quite differently, with colour masks/filters between the backlight and the LCD, which means they cannot be "transflective" like traditional LCD can be.

@dariods8474 have you considered e-ink displays? Their contrast gets better the more light falls on them.

4

I have tried a few e-link displays, which are indeed highly readable outdoors.

But as yet, I have not found one that does not have the real real slow screen write and refresh, so suggestions welcomed.

5

E-ink display too expensive. I just want to know if anyone has used these displays in sunlight. There are many videos on youtube but none show it in sunlight

6

I have used exactly that type of display (the red TFT) outdoors in sunlight, they are next to invisible.

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I seem to remember a "transflective LCD" from days of yore that had that characteristic.

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But these displays do have a backlight. Still they not readable in sunlight? Do you have one now?

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I still have several of those TFT displays, do you want me to count how many I have ?

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I would be thankful to you if you could post a pic of working display in daylight, a demo program would be okay

11

Here we go, not in the brightest of sunlight, its winter here, and there was a slight bit of haze in the air. First is display pointing at sun, displaying is text as you cannot see. Second is display pointing away from sun so in shade.

Pointing at Sun
Pointing at Sun881×702 70.7 KB

Shaded from Sun
Shaded from Sun1000×740 74.2 KB

1 Like
12

Are these photos with backlight LED on?

13

Of course.

If you dont turn on the 'backlight' there is no visible output from the display.

Have you used a TFT display before ?

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No, trying for the first time. I had an idea that without the led backlight on it would not display anything but I thought why not ask and confirm rather than assume.

15

Have you worked out what text messages are on the TFT screen, you can just about see text on the image that is in the shade ?

You have not said what your project actually is or what you want to display in 'daylight' ....................

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What I was displaying was as in the pic. I need some big fonts and more display characters

IMG_20241216_145440
IMG_20241216_1454401920×1446 85.3 KB

17

Search for something like this transflective display.

Screenshot 2025-01-27 at 3.10.18 PM
Screenshot 2025-01-27 at 3.10.18 PM1208×848 120 KB

18

128*64 serial GLCD display with green backlit is costing me INR500 and this display a parallel interface is costing INR 2300.

19

Can I connect a 5V 128x64 serial GLCD to esp32?

20

Probably, if you use suitable logic level conversion circuits.

Lots of tutorials to be found on how to do it.