TeensyLC : output integer to 8x7-segment MAX7219 LED display, with no leading zeroes

gistfile1.txt

// TeensyLC MAX7219 7-Segment Sample.
// https://www.pjrc.com/teensy/td_libs_LedControl.html

#include <Arduino.h>
#include <LedControl.h>

/*
 * Inputs: DIN pin, CLK pin, LOAD pin, number of digits
 *
 * Note: one MAX7219 chip drives 8x8 LEDs. With a 7-segment
 * module, this corresponds to 8 digits with 7 segment LEDs plus
 * one dot LED each.
 *
 * The least significant (rightmost) digit is at position 0.
 *
 * Sample unit: Amazon B07D8ZC7Q3
 */
LedControl display = LedControl(14, 16, 15, 8);

/*
 * Emit number n to passed-in LedControl display.
 * Show the decimal number.
 * Leading zero digits will be blanked.
 *
 * Millions and thousands dots will be set, adapt if
 * you expect higher numbers and have more than 8
 * 7-segment devices.
 */
void showNumber(LedControl display, unsigned int n) {
  int pos = 0; // start with least significant digit (ones)
  while(pos < display.getDeviceCount()) {
    display.setDigit(0, pos, n % 10, pos == 3 || pos == 6);
    pos++;
    n /= 10;
    if(n == 0) {
      break;
    }
  }
  while(pos < display.getDeviceCount()) {
    display.setChar(0, pos++, ' ', false);
  }
}

void setup() {
  display.shutdown(0, false);   // turns on display
  display.setIntensity(0, 3);   // 15 = brightest
}

unsigned int n = 1001234;       // Start with 1.001.234
void loop() {
  showNumber(display, n--);
}