MAX7219 Counter Demo

main.cpp

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

#define SPINNER_SPEED 5
#define SPINNER_LENGTH 2

LedControl lc=LedControl(3, 4, 5, 1);
long num = 0;

void showNumber(long number, byte pos = 0) {
  byte digit = number % 10;
  lc.setDigit(0,pos,digit,false);
  long remainingDigits = number / 10;
  if (remainingDigits > 0) {
    showNumber(remainingDigits, pos + 1);
  }
}

void drawSpinner(long num, byte length = 3, byte pos = 7) {
  for (byte i = 0; i <= length ; i++) {
    lc.setLed(0, pos, 1 + (num/SPINNER_SPEED+i) % 6, (i != 0));
  }
}

void setup() {
  lc.shutdown(0,false);
  lc.setIntensity(0,15);
  lc.clearDisplay(0);
}

void loop() {
  showNumber(num);
  drawSpinner(num, SPINNER_LENGTH);
  num++;
}