I received my PicoCalc about two weeks ago, and I’m loving using PicoMite (or technically WebMite, as I stuck a Pico 2W in it). However, I started programming a GUI shell for it, as I’ve come from a graphing calculator hacking background (I have a collection of TI calculators), and one little annoyance I’ve discovered is that clearing the screen with white doesn’t make the screen actually full white; at first it looks fine, but drawing anything, text, boxes, whatever, will cause bright horizontal bands to appear on the rows containing the additionally drawn things. It’s really strange, and kind of difficult to describe, so here’s a little illustration that decently accurately depicts what I’m seeing. (This is an excerpt of the design mockup of my shell, not a screenshot)
Seems like depending on how many non-white pixels there are on any row, it decreases or increases the brightness of the white pixels; this banding only appears when the background is RGB(240, 240, 240) or higher; anything else (bright colors, pastels, dark colors, black, etc.) is unaffected by this strange effect, and smaller elements like a 128x128 white box on a non-white background are also unaffected. I’ve run some tests to ensure this isn’t due to a quirk with how PicoMite clears the screen (by filling the screen with lots of white rectangles, which resulted in the same thing, and then downloading a screenshot to see if it displayed the same effect, which it didn’t), and it seems to be entirely an issue with the LCD. I’m pretty sure I didn’t damage my LCD during a module swap, since it’s looked like this even before changing out my Pico, and I was very careful during the initial assembly.
This is, to be clear, an annoyance, and not a debilitating issue. I would really like to know why it does this, though, and if anyone else has this problem. Thanks!
