I tried writing some strings to the MCUFRIEND 3.95 inch ili9488 LCD, left text on it a few minutes, and the image of what I wrote stuck as if burned in. I loaded the GLUE demo for random screens and it washed out back to normal after about 30 seconds.
What are we going to do about this ?
The display is extremely bright, I am trying to find where in the MCUFriend_kbv I can reduce the brightness. I need to anyway because in some demos I get far too much brightness and contrast that shows grid-lines and a medium grey background. It should be black, and when viewed beyond about a 45° angle, it appears normal.
A little info on the burn-in :
You appear to have chosen to use a Pro Mini instead of a proper Uno.
This will be fine if you connect every pin correctly.
In other posts you seem to have decided various things according to "some have said".
I suggest that you buy a regular Uno clone and just plug the Shield in as nature intended.
And if you have serious concerns about "some have said", you quote where and who "said" what.
David.
It's been on a UNO now. I used the Pro Mini for until the UNO arrived. Other than some longer wires, what difference would the same CPU be for this on two different boards after the setup and display ram are programmed. I was hoping to find a shortcut to info on brightness and contrast.
This forum is a hobby forum, we sort of get the stuff in raw form and experiment. Not much documentation in an Intel type format.
I'm a little tired to keep track of all the details, In the last few months I took on BASCOM AVR, Great Cow Basic, XC8, XC16, MPLABS, Visual Studios 2015, had to relearn DOS, and Qbasic for some projects I am working on.
Considering it could take several months to re-engineer an LCD panel from the diffuse documentation, I thought is was reasonable request from a person of my lowly status in this corner of the electronics industry.
This is a joke, and truth, yes I expect my component manuals to be delivered to me on a silver office cart, by a humble woman who puts the documentation in a brown paper bag I hold at a 45 degree angle so that she will not touch the sides of the manual with the bag.
I have a 3.95" Mcufriend UNO Shield. I have just plugged it into a Uno.
The display is crisp and clear. The contrast is good. The backlight is less bright than the Blue 2.8" ILI9341 alongside it.
The Red 3.95" screen is cool to the touch. The Blue 2.8" screen is slightly warm to the touch.
I have it displaying "testcard_kbv.ino" sketch. It does not seem to "burn in" on any shield that I have tried.
Of course, your 3.95" might be different to my one. You have a lot of "some have said" theories but no quotes. Likewise, your after hours occupation may be incompatible.
David.
I don't go pointing my finger at everyone, I'm usually not a time wasting spear chucker. I just wanted to see if I could find an easy way to adjust the screen.
I would like to toss the spears aside, and make some friends by working out a screen adjustment function probably with a few buttons and screen adjustment window.
I would simply pay Microchip for their VGDD software, I can't buy everything I want. You should see how fantastic THAT is.
And I do want to toss in of all the software I learned to somewhat use, Arduino is of the easiest C style IDE's. I got hung up on library management a few days because I attempted a sort of scratchpad library directory that confused the IDE. Got that fixed and it's really easy now.
In case the Arduino team reads this, this IDE is as good as the pay before you play software. I thought it would be well, not so well done. I intend to donate sometime soon.
The test that showed the image stick is the scroll demo in the MCUFriend lib. It draws brilliant white characters on a medium grey background, intended to be black.
I changed portrait to landscape, removed the scroll routine in the main loop, replaced it with two lines of text, changed the delay to 5000ms. It prints two lines, waits 5 seconds then repeats, the screen will fill with those brilliant white letters.
I have just run the "scroll_kbv.ino" example from the MCUFRIEND_kbv v2.8 library.
It behaves just fine on my 3.95" Uno Shield. White text on a Black background.
Examples are there to show you how to do things. Nothing more.
If you have a medium grey background with brilliant white text, it sounds as if your backlight is far too bright. Does your screen feel very warm?
I would look at the "testcard_kbv.ino" sketch to see whether the colours are correct.
And look at the "graphictest_kbv.ino" sketch to see any smearing, blurring, ghosting, ...
If you are not happy, perhaps you should go back to brain surgery.
David.
It runs the 320x480 GLUE demo ok, and makes perfect levels. I tried other iLi ID's and one produced perfect video levels , display_string example and forcing 9481 made perfect levels but in reverse. As with some other person wrote, I could see it perfectly with a mirror.
It doesn't take much change to make a large difference in display saturation. Look at how twitchy the 2004 or 1602 lcd's can be. Since nothing is in the screen but saturated white and pure black, I will look at the dynamic contrast settings. I can almost see again, I was so tired I could look at the screen and not focus or take much in. Maybe in a day or two I will recover from pushing myself too hard.
And yes I can see this is a learning place for students and tinkerers. A person can learn a lot by exploring these things.
I messed around with readpixel_kbv and it is doing well. The background is a slight grey and the characters are not excessively bright, no burn-in (ghost image).