#include "ESP32-HUB75-MatrixPanel-I2S-DMA.h" MatrixPanel_I2S_DMA *dma_display = nullptr; extern "C" void app_main() { HUB75_I2S_CFG mxconfig(/* width = */ 64, /* height = */ 64, /* chain = */ 1); dma_display = new MatrixPanel_I2S_DMA(mxconfig); dma_display->begin(); dma_display->setBrightness8(80); dma_display->clearScreen(); // `println` is only available when the Adafruit GFX library is used. dma_display->println("Test message"); }