#include "SPI.h"
#include "DMD2.h"
#include "TimerOne.h"
#include "Arial114.h"

/*-----------------------------------------------------------------------
 Only 7 of the 16 pins on the DMD are actually used:
 GND - Hopefully obvious
 nOE - Enable / Disable ALL the LEDs on the DMD
 A - A&B pins select which 1/4 of the DMD is selected
 B - A&B pins select which 1/4 of the DMD is selected
 CLK - Used to clock each pixel into the DMD shift registers
 SCLK - Latches the current content of the DMD shift registers
 R - The raw pixel data stream (NB: The 'R' stands for RED. You might notice an unused 'G' pin which is for Green on a HUB12 connector)
 --------
 nOE(D9) |1     2| A(D6)
 Gnd     |3     4| B(D7)
 Gnd     |5     6| C
 Gnd     |6     8| CLK(D13)
 Gnd     |7    10| SCLK(D8)
 Gnd     |11   12| R(D11)
 Gnd     |13   14| G
 Gnd     |15   16| D
 ---------
 -----------------------------------------------------------------------*/
//Fire up the DMD library as dmd
#define DISPLAYS_ACROSS 1
#define DISPLAYS_DOWN 1
DMD dmd(DISPLAYS_ACROSS, DISPLAYS_DOWN);

/*-----------------------------------------------------------------------
 Interrupt handler for Timer1 (TimerOne) driven DMD refresh scanning, this gets
 called at the period set in Timer1.initialize();
 -----------------------------------------------------------------------*/
void ScanDMD()
{
  dmd.scanDisplayBySPI();
}

const byte PanelWidth = 32;
const byte MaxStringLength = 5;
char CharBuf[MaxStringLength + 1];

void setup() {
  //initialize TimerOne's interrupt/CPU usage used to scan and refresh the display
  Timer1.initialize( 5000 );          //period in microseconds to call ScanDMD. Anything longer than 5000 (5ms) and you can see flicker.
  Timer1.attachInterrupt( ScanDMD );  //attach the Timer1 interrupt to ScanDMD which goes to dmd.scanDisplayBySPI()
  dmd.selectFont(Arial114);
}

void loop() {
  String myString;
  myString= "0"; center_theDisplay(myString); delay(1000);
  myString= "12"; center_theDisplay(myString); delay(1000);
  myString= "345"; center_theDisplay(myString); delay(1000);
  myString= "678."; center_theDisplay(myString); delay(1000);
}

void center_theDisplay(String input_Str) {
  byte charCount, total_charWidth, x_position;
  input_Str.toCharArray(CharBuf, MaxStringLength + 1); //string to char array

  charCount=  input_Str.length();
  if (charCount==0) exit;

  total_charWidth= 0;
  for (byte thisChar = 0; thisChar <charCount; thisChar++) {
    total_charWidth= total_charWidth + dmd.charWidth(CharBuf[thisChar]) +1; //add 1 pixel for space
  }

  total_charWidth= total_charWidth -1; //no space for last letter
  x_position= (PanelWidth - total_charWidth) /2; //position(x) of first letter
  dmd.clearScreen(true);

  for (byte thisChar = 0; thisChar <charCount; thisChar++) {
    //dmd.drawChar(x, y,‘@', GRAPHICS_NORMAL)
    dmd.drawChar( x_position,  1, CharBuf[thisChar], GRAPHICS_NORMAL );
    x_position= x_position + dmd.charWidth(CharBuf[thisChar]) + 1; //position for next letter
  }
}