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Thread: OctoWS2811 Teensy 3.6 VideoDisplay not working properly

  1. #1
    Junior Member
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    OctoWS2811 Teensy 3.6 VideoDisplay not working properly

    Hi everyone!

    I am currently working on a 24x24 LED display using the OctoWS2811 library with one teensy board, and following the instructions provided on the PJRC website.

    I am using the original code provided, just replacing the LED_WIDTH and LED_HEIGHT to fit my project, however instead of all the LEDs lighting up, only the first three rows light up - so instead of 576 lights, only 72 LEDs light up.

    Code:
    #define LED_WIDTH      24   // number of LEDs horizontally
    #define LED_HEIGHT     24   // number of LEDs vertically (must be multiple of 8)
    #define LED_LAYOUT     0    // 0 = even rows left->right, 1 = even rows right->left
    
    #define VIDEO_XOFFSET  0
    #define VIDEO_YOFFSET  0       // display entire image
    #define VIDEO_WIDTH    100
    #define VIDEO_HEIGHT   100
    
    const int ledsPerStrip = LED_WIDTH * LED_HEIGHT /8;
    My original speculation was that it was an issue with the code that defines the ledsPerStrip, so I tried setting LED_HEIGHT to 192 (so that the total LEDs would equal to 576), and while that turned on all the LEDs it elongated the image in processor and the final result was a distorted compressed image. I am not receiving any code error messages, and have checked my wiring and everything seems to be in order.

    Any advice would be appreciated!

    Specs:

  2. #2
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    @kern:

    You say that you have checked your wiring, but you don't give any info on how that wiring is actually done. Without specific wiring info, it's hardly possible to provide any useful help !!

    Since the OctoWS2811 drives the LEDs using 8 pins, exactly how do you have your LED strips wired to those 8 pins ??

    I'm sure that you noticed the following comment(s) in the example code (specifically "When 16, 24, 32 are used, each strip spans 2, 3, 4 rows."):

    Code:
    // The actual arrangement of the LEDs connected to this Teensy 3.0 board.
    // LED_HEIGHT *must* be a multiple of 8.  When 16, 24, 32 are used, each
    // strip spans 2, 3, 4 rows.  LED_LAYOUT indicates the direction the strips
    // are arranged.  If 0, each strip begins on the left for its first row,
    // then goes right to left for its second row, then left to right,
    // zig-zagging for each successive row.
    #define LED_WIDTH      60   // number of LEDs horizontally
    #define LED_HEIGHT     32   // number of LEDs vertically (must be multiple of 8)
    #define LED_LAYOUT     0    // 0 = even rows left->right, 1 = even rows right->left
    With your LED_WIDTH set to 24, might that partially explain your 3 rows of lit LEDs ?? Hard to tell without knowing your exact wiring setup.

    Mark J Culross
    KD5RXT

  3. #3
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    Ah sorry forgot to mention! I am using an octoboard, which from my understanding does the wiring for me. As for wiring of the strips it's the same layout as the example in the website.

    (I am quite new to this so I apologize in advance for any stupidity!)

  4. #4
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    @kern:

    Please understand that I am not being critical . . . I really do want to try & help you to solve your problem !! You have stated that you have 576 LEDs. However, I still don't know how you have them wired. Just saying "the same layout as the example" is inconclusive. The website shows three different cases: 1) 30 LEDs on each of 8 pins, 2) 10 LEDs on pin 1, 30 LEDs on pin 3, 5 LEDs on pin 4, & 20 LEDs on pin 6, 3) Do you have all 576 LEDs wired to a single pin ?? Do you have 288 LEDs wired to pin 1 & 288 LEDs wired to pin 6 ?? Do you have 72 LEDs (3 x 24) wired to each of the 8 pins ?? I would guess that you have the third choice, but it is still a guess !!

    Mark J Culross
    KD5RXT

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