SevSeg + FlexiTimer2

sevseg_ex2.ino

#include <SevSeg.h>
#include <FlexiTimer2.h>

SevSeg sevseg; //Instantiate a seven segment object

void setup() {
  byte numDigits = 4;
  byte digitPins[] = {3, 2, 1, 0};
  byte segmentPins[] = {11, 10 ,9 ,8, 7, 6, 5, 4};
  //sevseg.begin(COMMON_CATHODE, numDigits, digitPins, segmentPins);
  sevseg.begin(COMMON_ANODE, numDigits, digitPins, segmentPins);

  sevseg.setNumber(1000,0);
  sevseg.setBrightness(5);

  FlexiTimer2::set(10, flash);
  FlexiTimer2::start();
}

void loop() {
  // put your main code here, to run repeatedly:
  for (int i = 0; i < 9999; i++) {
    sevseg.setNumber(i,-1);
    delay(100);
  }
}

void flash() {
  sevseg.refreshDisplay();
}