Update

ESP32-HUB75-MatrixPanel-I2S-DMA.cpp

@@ -754,7 +754,7 @@ void MatrixPanel_I2S_DMA::brtCtrlOE(int brt, const bool _buff_id){
 /*
  *  overload for compatibility
  */
-bool MatrixPanel_I2S_DMA::begin(int r1, int g1, int b1, int r2, int g2, int b2, int a, int b, int c, int d, int e, int lat, int oe, int clk){
+bool MatrixPanel_I2S_DMA::begin(int r1, int g1, int b1, int r2, int g2, int b2, int a, int b, int c, int d, int e, int lat, int oe, int clk) {
 
   // RGB
   m_cfg.gpio.r1 = r1; m_cfg.gpio.g1 = g1; m_cfg.gpio.b1 = b1;

ESP32-HUB75-MatrixPanel-I2S-DMA.h

@@ -350,6 +350,8 @@ class MatrixPanel_I2S_DMA {
 
     /* Propagate the DMA pin configuration, allocate DMA buffs and start data ouput, initialy blank */
     bool begin(){
+
+	  if (initialized) return; // we don't do this twice or more!
 
       // Change 'if' to '1' to enable, 0 to not include this Serial output in compiled program        
       #if SERIAL_DEBUG       

examples/1_SimpleTestShapes/1_SimpleTestShapes.ino

@@ -111,9 +111,6 @@ void setup() {
   dma_display->clearScreen();
   dma_display->fillScreen(myWHITE);
 
-//
-  dma_display->begin(); // use default pins  
-
   // fix the screen with green
   dma_display->fillRect(0, 0, dma_display->width(), dma_display->height(), dma_display->color444(0, 15, 0));
   delay(500);