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Thread: Adafruit RA8875 the Sumotoy libray and the Teensy 3.6 = distorted graphics

  1. #1

    Adafruit RA8875 the Sumotoy libray and the Teensy 3.6 = distorted graphics

    I have a 5" Adafruit touch display, the Adafruit RA8875 driver board a Teensy 3.6 all connected. When I run an Adafruit example it looks great. When I try one of the Sumotoy library examples things get weird. It's a bit distorted like an old TV that's out of sync (those of you old enough recall scramble porn on HBO) sort of like that.

    In my searches I ran across references to lowering the SPI speed. I tried that ( think I did it correctly ) but to no adavantage. The initial culprit is often the wiring and wire lengths but the fact the Adafruit library is fine leads me away from that for now (unless Sumotoy runs it higher). I tried various branches of their library with no difference.

    I'm hoping somone might have ran into this and have some insights. Below is it running the Adafruit.

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    This is the Sumotoy clock example.

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  2. #2
    Senior Member+ mjs513's Avatar
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    Jul 2014
    New York
    I have one of these displays as well. Just a quick thought did you remember to use "Adafruit_800x480" instead of "RA8875_800x480"? Had to ask.

    The Sumotoy library is a bit out dated and i don't really really use that version. A few of us did some modifications and updates of the library to get it to work with the T4 but I can't remember how much testing of this version we did on T3.6... I you are interested you can try this version Sumotoy's library:, [/QUOTE]

    EDIT: if you do search for RA8875 on the forum:

    there are more....

  3. #3
    I did use Adafruit_800x480. However, I don't believe I've tried that version of the library. I'll give a try.

    It's as if there is some sync issue when the display tries to draw about half way across.

  4. #4
    OK, I found that I was still using a default library in C: after turning on the verbose warnings.

    The library suggested renders this for the clock example now. It's not wavy now but the lines are obviously not correct.

    Click image for larger version. 

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    The blue screen was with the original library's pattern example.
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    Last edited by CRC; Yesterday at 05:11 PM.

  5. #5
    Seems the only one that works normally for me is the default .70. Otherwise text goes to odd places and I get those lines in the clock.

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