  * DIN          |  12
  * CLK          |  13
  * CS (default) |  15
+ *
+ * Wiring for ESP32 follows the default for the ESP32 SD Library, see: https://github.com/espressif/arduino-esp32/tree/master/libraries/SDis is on the default Teensy 3.1 SPI pins, and chip select can be on any GPIO,
  *
  * This code first looks for .gif files in the /gifs/ directory
  * (customize below with the GIF_DIRECTORY definition) then plays random GIFs in the directory,


    matrix.setBrightness(defaultBrightness);

    // for large panels, set the refresh rate lower to leave more CPU time to decoding GIFs (needed if GIFs are playing back slowly)
    //matrix.setRefreshRate(90);

    // for large panels on ESP32, set the calculation refresh rate divider lower to leave more CPU time to decoding GIFs (needed if GIFs are playing back slowly)
    //matrix.setCalcRefreshRateDivider(4);

#if !defined(ESP32)
    matrix.begin();
#endif

    // Clear screen

 *    set kRefreshDepth=24 and kDmaBufferRows=2 or set USB Type: "None" in Arduino,
 *    decrease refreshRate in setup() to 90 or lower to get good an accurate GIF frame rate
 *  - Set the chip select pin for your board.  On Teensy 3.5/3.6, the onboard microSD CS pin is "BUILTIN_SDCARD"
 *  - For ESP32 and large panels, you don't need to lower the refreshRate, but you can lower the frameRate (number of times the refresh buffer
 *    is updaed with new data per second), giving more time for the CPU to decode the GIF.
 *    Use matrix.setMaxCalculationCpuPercentage() or matrix.setCalcRefreshRateDivider()
 */

#if defined (ARDUINO)
