test.cpp

#include "LedControl.h"

/*
 Now we need a LedControl to work with.
 ***** These pin numbers will probably not work with your hardware *****
 pin 12 is connected to the DataIn 
 pin 11 is connected to the CLK 
 pin 10 is connected to LOAD 
 We have only a single MAX72XX.
 */
LedControl lc=LedControl(10,8,9,1);
/* we always wait a bit between updates of the dis
play */
unsigned long delaytime=100;

int numbers[] = {
  0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
  0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1,
  0, 1, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 1,
  1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 0,
  0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 0, 0, 1, 0,
  1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0,
  0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0,
  1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0,
  0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 0,
  0, 1, 1, 0, 1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 1, 0, 1, 1, 0
};

void setup() {
  Serial.begin(9600);

  /* The MAX72XX is in power-saving mode on startup, we have to do a wakeup call */
  lc.shutdown(0,false);
  /* Set the brightness to a medium values */
  lc.setIntensity(0, 1);
  /* and clear the display */
  lc.clearDisplay(0);
}

void printNumber(int num, int offsetX, int offsetY) {
  int numOffset = num * (5 * 4);
  for(int x = 0; x < 4; x++) {
    for(int y = 0; y < 5; y++) {
      int onOff = numbers[numOffset + x + y * 4];
      lc.setLed(0, 7 - (x + offsetX), y + offsetY, onOff == 1);
    }    
  }
}

void loop() {
  for(int i = 0; i < 64; i++) {
    int poti = analogRead(0); // A value between 0 1nd 1023
    int v = poti * 64 / 1024; // We have only 64 LEDs, so scale the 1024 steps of the potentiometer down to 64

    int i0 = poti * 10 / 1024;
    int i1 = (poti * 100 / 1024) % 10;
    int i2 = poti * 9 / 1024;

    printNumber(i0, 2, 1);

    for(int i = 0; i < 8; i++) {
      lc.setLed(0, i, 7, i < i2);
    }
  }
}