#include <DMD32.h> 
#include <fonts/SystemFont5x7.h>
#include <fonts/Arial_Black_16_ISO_8859_1.h>

//Fire up the DMD library as dmd
#define DISPLAYS_ACROSS 1
#define DISPLAYS_DOWN 1
#define LED_BUILTIN 14

DMD dmd(DISPLAYS_ACROSS, DISPLAYS_DOWN);

   //Timer setup
  //create a hardware timer  of ESP32
hw_timer_t * timer = NULL;

void IRAM_ATTR triggerScan()
{
  digitalWrite(LED_BUILTIN,HIGH);
  dmd.scanDisplayBySPI();
  digitalWrite(LED_BUILTIN,LOW);
}

void setup(void)
{
  
  pinMode(PIN_OTHER_SPI_nCS, OUTPUT);  //VSPI SS
  digitalWrite(PIN_OTHER_SPI_nCS,HIGH);

  timer = timerBegin(1000000);
  timerAttachInterrupt(timer,&triggerScan);
  timerAlarm(timer,1000,true,0);
   //clear/init the DMD pixels held in RAM
   dmd.clearScreen( false );   //true is normal (all pixels off), false is negative (all pixels on)
  Serial.begin(115200);
}

void loop(void)
{
   dmd.clearScreen( false );
   delay(500);
   dmd.clearScreen( true );
   delay(500);
}