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Thread: Teensy 4.0 with OctoWS2811 - movie2serial and videodisplay random colors

  1. #1
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    Teensy 4.0 with OctoWS2811 - movie2serial and videodisplay random colors

    Hello everyone, this is my first Teensy project and my first forum post, so please be patient with me.

    I have tried to search the forums, review the code and libraries, and troubleshoot code and hardware many ways before posting, but still have not identified the issue. Here is the summary and details...

    Summary: I am working on a LED strip display for a non-profit charity, with Teensy 4.0 with OctoWS2811, using original movie2serial in Processing 3 and original videodisplay in Teensyduino 1.53, the video displays on the screen but the LED strips appear to have very random colors that don't seem to match the color scheme of the video or the patterns of the video, even though the LEDs are changing/flashing as the video plays. I know you prefer including source code, but for this first round of testing, it is literally the movie2serial and videodisplay code included with the octows2811 library, with only the updated variables to get it running.

    More Details:
    • Using BasicTest or RainbowTest, I have confirmed the Teensy4.0 and OctoWS2811 are driving the LED strips as expected with proper colors (indicating to me the issue is with the movie2serial side, not hardware)
    • I believe I have the latest Octows2811 library installed with support for Teensy 4.x
    • Trying to review the octows2811 library code and the movie2serial code, I have been focusing on the image2data and colorwiring functions, but can't figure out what may be causing this issue?


    Do you have any recommendations or guidance on how to resolve this issue? Is there something different with the movie2serial code that needs to change for the Teensy4.0 and how the pixel data is being delivered over to the videodisplay code?

    Thank you for any advice and help!

  2. #2
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    Hello all, are there important details missing in my question, or do I need to restructure my question to get anyone to respond?

    Thank you,
    Jason

  3. #3
    Senior Member PaulStoffregen's Avatar
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    Oh, these probably need to updated for Teensy 4.....

  4. #4
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    Hello Paul, can you please help clarify that comment for me?

    Does this mean that there are code changes that will need to be made for movie2serial and/or displayvideo to make this work with Teensy 4.0?
    Does this mean if I am trying to get this working in the next week that I should consider switching to Teensy 3.1/3.2 with OctoWS2811 instead of Teensy 4.0?
    Or, does this mean something else entirely?

    I thought that you had already updated the OctoWS2811 library to support Teensy 4.0, so that's why I was going this route. If this is the wrong combination, please just let me know so I can pivot to another option.

    Thank you,
    Jason

  5. #5
    Senior Member PaulStoffregen's Avatar
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    I've added a VideoDisplay_Teensy4 example to OctoWS2811.

    https://github.com/PaulStoffregen/Oc...896f43eb71ef41

    This should solve the problem you're seeing. For more explanation, see the comment on the function I added at the end.

    Here's a complete copy of that new example. You should be able to just copy this into an Arduino window and upload it to your Teensy 4.0 to make it work with the Processing movie2serial program.

    Code:
    /*  OctoWS2811 VideoDisplay.ino - Video on LEDs, from a PC, Mac, Raspberry Pi
        http://www.pjrc.com/teensy/td_libs_OctoWS2811.html
        Copyright (c) 2020 Paul Stoffregen, PJRC.COM, LLC
    
        Permission is hereby granted, free of charge, to any person obtaining a copy
        of this software and associated documentation files (the "Software"), to deal
        in the Software without restriction, including without limitation the rights
        to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
        copies of the Software, and to permit persons to whom the Software is
        furnished to do so, subject to the following conditions:
    
        The above copyright notice and this permission notice shall be included in
        all copies or substantial portions of the Software.
    
        THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
        IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
        FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
        AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
        LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
        OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
        THE SOFTWARE.
    
    Update: The movie2serial program which transmit data has moved to "extras"
    https://github.com/PaulStoffregen/OctoWS2811/tree/master/extras
     
      Required Connections
      --------------------
        pin 2:  LED Strip #1    OctoWS2811 drives 8 LED Strips.
        pin 14: LED strip #2    All 8 are the same length.
        pin 7:  LED strip #3
        pin 8:  LED strip #4    A 100 to 220 ohm resistor should used
        pin 6:  LED strip #5    between each Teensy pin and the
        pin 20: LED strip #6    wire to the LED strip, to minimize
        pin 21: LED strip #7    high frequency ringining & noise.
        pin 5:  LED strip #8
        pin 15 & 16 - Connect together, but do not use
        pin 4:  Do not use
        pin 3:  Do not use as PWM.  Normal use is ok.
        pin 12: Frame Sync
    
        When using more than 1 Teensy to display a video image, connect
        the Frame Sync signal between every board.  All boards will
        synchronize their WS2811 update using this signal.
    
        Beware of image distortion from long LED strip lengths.  During
        the WS2811 update, the LEDs update in sequence, not all at the
        same instant!  The first pixel updates after 30 microseconds,
        the second pixel after 60 us, and so on.  A strip of 120 LEDs
        updates in 3.6 ms, which is 10.8% of a 30 Hz video frame time.
        Doubling the strip length to 240 LEDs increases the lag to 21.6%
        of a video frame.  For best results, use shorter length strips.
        Multiple boards linked by the frame sync signal provides superior
        video timing accuracy.
    
        A Multi-TT USB hub should be used if 2 or more Teensy boards
        are connected.  The Multi-TT feature allows proper USB bandwidth
        allocation.  Single-TT hubs, or direct connection to multiple
        ports on the same motherboard, may give poor performance.
    */
    
    #include <OctoWS2811.h>
    
    // 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
    
    // The portion of the video image to show on this set of LEDs.  All 4 numbers
    // are percentages, from 0 to 100.  For a large LED installation with many
    // Teensy 3.0 boards driving groups of LEDs, these parameters allow you to
    // program each Teensy to tell the video application which portion of the
    // video it displays.  By reading these numbers, the video application can
    // automatically configure itself, regardless of which serial port COM number
    // or device names are assigned to each Teensy 3.0 by your operating system.
    #define VIDEO_XOFFSET  0
    #define VIDEO_YOFFSET  0       // display entire image
    #define VIDEO_WIDTH    100
    #define VIDEO_HEIGHT   100
    
    //#define VIDEO_XOFFSET  0
    //#define VIDEO_YOFFSET  0     // display upper half
    //#define VIDEO_WIDTH    100
    //#define VIDEO_HEIGHT   50
    
    //#define VIDEO_XOFFSET  0
    //#define VIDEO_YOFFSET  50    // display lower half
    //#define VIDEO_WIDTH    100
    //#define VIDEO_HEIGHT   50
    
    
    const int ledsPerStrip = LED_WIDTH * LED_HEIGHT / 8;
    
    DMAMEM int displayMemory[ledsPerStrip*6];
    int drawingMemory[ledsPerStrip*6];
    int incomingMemory[ledsPerStrip*6];
    elapsedMicros elapsedUsecSinceLastFrameSync = 0;
    
    const int config = WS2811_800kHz; // color config is on the PC side
    
    OctoWS2811 leds(ledsPerStrip, displayMemory, drawingMemory, config);
    
    void setup() {
      pinMode(12, INPUT_PULLUP); // Frame Sync
      Serial.setTimeout(50);
      leds.begin();
      leds.show();
    }
    
    void loop() {
    //
    // wait for a Start-Of-Message character:
    //
    //   '*' = Frame of image data, with frame sync pulse to be sent
    //         a specified number of microseconds after reception of
    //         the first byte (typically at 75% of the frame time, to
    //         allow other boards to fully receive their data).
    //         Normally '*' is used when the sender controls the pace
    //         of playback by transmitting each frame as it should
    //         appear.
    //   
    //   '$' = Frame of image data, with frame sync pulse to be sent
    //         a specified number of microseconds after the previous
    //         frame sync.  Normally this is used when the sender
    //         transmits each frame as quickly as possible, and we
    //         control the pacing of video playback by updating the
    //         LEDs based on time elapsed from the previous frame.
    //
    //   '%' = Frame of image data, to be displayed with a frame sync
    //         pulse is received from another board.  In a multi-board
    //         system, the sender would normally transmit one '*' or '$'
    //         message and '%' messages to all other boards, so every
    //         Teensy 3.0 updates at the exact same moment.
    //
    //   '@' = Reset the elapsed time, used for '$' messages.  This
    //         should be sent before the first '$' message, so many
    //         frames are not played quickly if time as elapsed since
    //         startup or prior video playing.
    //   
    //   '?' = Query LED and Video parameters.  Teensy 3.0 responds
    //         with a comma delimited list of information.
    //
      int startChar = Serial.read();
    
      if (startChar == '*') {
        // receive a "master" frame - we send the frame sync to other boards
        // the sender is controlling the video pace.  The 16 bit number is
        // how far into this frame to send the sync to other boards.
        unsigned int startAt = micros();
        unsigned int usecUntilFrameSync = 0;
        int count = Serial.readBytes((char *)&usecUntilFrameSync, 2);
        if (count != 2) return;
        count = Serial.readBytes((char *)incomingMemory, sizeof(incomingMemory));
        if (count == sizeof(incomingMemory)) {
          copyIncomingToDrawing();
          unsigned int endAt = micros();
          unsigned int usToWaitBeforeSyncOutput = 100;
          if (endAt - startAt < usecUntilFrameSync) {
            usToWaitBeforeSyncOutput = usecUntilFrameSync - (endAt - startAt);
          }
          digitalWrite(12, HIGH);
          pinMode(12, OUTPUT);
          delayMicroseconds(usToWaitBeforeSyncOutput);
          digitalWrite(12, LOW);
          // WS2811 update begins immediately after falling edge of frame sync
          digitalWrite(13, HIGH);
          leds.show();
          digitalWrite(13, LOW);
        }
    
      } else if (startChar == '$') {
        // receive a "master" frame - we send the frame sync to other boards
        // we are controlling the video pace.  The 16 bit number is how long
        // after the prior frame sync to wait until showing this frame
        unsigned int usecUntilFrameSync = 0;
        int count = Serial.readBytes((char *)&usecUntilFrameSync, 2);
        if (count != 2) return;
        count = Serial.readBytes((char *)drawingMemory, sizeof(drawingMemory));
        if (count == sizeof(drawingMemory)) {
          digitalWrite(12, HIGH);
          pinMode(12, OUTPUT);
          while (elapsedUsecSinceLastFrameSync < usecUntilFrameSync) /* wait */ ;
          elapsedUsecSinceLastFrameSync -= usecUntilFrameSync;
          digitalWrite(12, LOW);
          // WS2811 update begins immediately after falling edge of frame sync
          digitalWrite(13, HIGH);
          leds.show();
          digitalWrite(13, LOW);
        }
    
      } else if (startChar == '%') {
        // receive a "slave" frame - wait to show it until the frame sync arrives
        pinMode(12, INPUT_PULLUP);
        unsigned int unusedField = 0;
        int count = Serial.readBytes((char *)&unusedField, 2);
        if (count != 2) return;
        count = Serial.readBytes((char *)drawingMemory, sizeof(drawingMemory));
        if (count == sizeof(drawingMemory)) {
          elapsedMillis wait = 0;
          while (digitalRead(12) != HIGH && wait < 30) ; // wait for sync high
          while (digitalRead(12) != LOW && wait < 30) ;  // wait for sync high->low
          // WS2811 update begins immediately after falling edge of frame sync
          if (wait < 30) {
            digitalWrite(13, HIGH);
            leds.show();
            digitalWrite(13, LOW);
          }
        }
    
      } else if (startChar == '@') {
        // reset the elapsed frame time, for startup of '$' message playing
        elapsedUsecSinceLastFrameSync = 0;
    
      } else if (startChar == '?') {
        // when the video application asks, give it all our info
        // for easy and automatic configuration
        Serial.print(LED_WIDTH);
        Serial.write(',');
        Serial.print(LED_HEIGHT);
        Serial.write(',');
        Serial.print(LED_LAYOUT);
        Serial.write(',');
        Serial.print(0);
        Serial.write(',');
        Serial.print(0);
        Serial.write(',');
        Serial.print(VIDEO_XOFFSET);
        Serial.write(',');
        Serial.print(VIDEO_YOFFSET);
        Serial.write(',');
        Serial.print(VIDEO_WIDTH);
        Serial.write(',');
        Serial.print(VIDEO_HEIGHT);
        Serial.write(',');
        Serial.print(0);
        Serial.write(',');
        Serial.print(0);
        Serial.write(',');
        Serial.print(0);
        Serial.println();
    
      } else if (startChar >= 0) {
        // discard unknown characters
      }
    }
    
    
    // The PC transmits data in the transposed format Teensy 3.x uses.
    // This copy function undoes the transpose, so the pixels are
    // put back into the simpler framebuffer format Teensy 4.x uses.
    void copyIncomingToDrawing() {
      const uint32_t width = (LED_WIDTH * LED_HEIGHT / 8) * 3;
      const uint8_t *src = (const uint8_t *)incomingMemory;
      uint8_t *dest = (uint8_t *)drawingMemory;
    
      for (uint32_t x=0; x < width; x++) {
        uint8_t b[8] = {0, 0, 0, 0, 0, 0, 0, 0};
        for (uint8_t mask = 0x80; mask; mask >>= 1) {
          uint8_t bits = *src++;
          if (bits & 0x01) b[0] |= mask;
          if (bits & 0x02) b[1] |= mask;
          if (bits & 0x04) b[2] |= mask;
          if (bits & 0x08) b[3] |= mask;
          if (bits & 0x10) b[4] |= mask;
          if (bits & 0x20) b[5] |= mask;
          if (bits & 0x40) b[6] |= mask;
          if (bits & 0x80) b[7] |= mask;
        }
        dest[width*0] = b[0];
        dest[width*1] = b[1];
        dest[width*2] = b[2];
        dest[width*3] = b[3];
        dest[width*4] = b[4];
        dest[width*5] = b[5];
        dest[width*6] = b[6];
        dest[width*7] = b[7];
        dest = dest + 1;
      }
    }

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