/*

http://www.bristolwatch.com/arduino/arduino_max7219c.htm
BCD Conversion with Arduino Displayed on MAX7219
Lewis Loflin lewis@bvu.net
This code comes with no warranty.

*/


*/
#define RB5  5  // CS
#define RB6  4  // DATA
#define RB7  6  // CLK

#define SW1  2 // white PB
#define SW2  3 // red PB

void setup()   {

  pinMode(RB5, OUTPUT);
  pinMode(RB6, OUTPUT);
  pinMode(RB7, OUTPUT);

  pinMode(SW1, INPUT);
  pinMode(SW2, INPUT);
  //pullups
  digitalWrite(SW1, HIGH);
  digitalWrite(SW2, HIGH);

  digitalWrite(RB5, 0);
  init_MAX7219();

}

int digit;
unsighed int count; 
char array1[10];

void loop()   {

  if (!digitalRead(SW1))   {
    count = 99999;
    for (int i = 0; i <= count; i++)   {
      bcdOut(i);
      delay(100);
      if (!digitalRead(SW2)) break;
    } // end for
  } //end if

}



int bcdOut(int j)   {

  // convert to BCD send to MAX7219

  // get 1st digit of j
  digit = j % 10; // MOD J
  writeMAX7219(1, digit);

  // get 2nd digit of j
  j = j / 10;
  digit = j % 10; // MOD j
  //  if (j == 0) digit = 0x0f;
  writeMAX7219(2, digit + 0x80);

  // get 3rd digit of j
  j = j / 10;
  digit = j % 10; // MOD j
  if (j == 0) digit = 0x0f;
  writeMAX7219(3, digit);

  // get 4th digit of j
  j = j / 10;
  digit = j % 10; // MOD j
  if (j == 0) digit = 0x0f;
  writeMAX7219(4, digit);

  // get 5th digit of j
  j = j / 10;
  digit = j % 10; // MOD j
  if (j == 0) digit = 0x0f;
  writeMAX7219(5, digit);

}


// note used reference only
// location is place on LCD display.
void typeInt(int k)   {
  char array1[10];
  itoa(k, array1, 10); // int to string
  // typeln(array1, location);
}



// shift data to MAX7219
// RB7 -> CLK, RB6 -> DATA, RB5 -> CS not
void ssrOut(unsigned char val)  {
  int j;
  for (j = 1; j <= 8; j++)  { // shift out MSB first
    unsigned char  temp = val & 0x80; // MSB out first
    if (temp == 0x80) digitalWrite(RB6, 1); // RB6 DATA
    else digitalWrite(RB6, 0);
    digitalWrite(RB7, 1);
    // delay(1);
    digitalWrite(RB7, 0);
    val = val << 1; // shift one place left
  }  // next j
}


void pulseCS(void)   {
  digitalWrite(RB5, 1);
  // delay(2);
  digitalWrite(RB5, 0);
}


void init_MAX7219(void)   {
  digitalWrite(RB5, 0); // CS NOT

  // set decode mode
  ssrOut(0x09); // address
  //	ssrOut(0x00); // no decode
  ssrOut(0xFF); // 4-bit BCD decode eight digits
  pulseCS();

  // set intensity 0x00 to 0x0f
  ssrOut(0x0A); // address
  ssrOut(0x08); // 7/32
  pulseCS();

  // set scan limit 0-7
  ssrOut(0x0B); // address
  // ssrOut(0x07); // 8 digits
  ssrOut(0x07); // 4 digits
  pulseCS();

  // clear MAX7219
  for (int i = 1; i <= 8; i++)   {
    ssrOut(i);
    ssrOut(0x0F);
    pulseCS();
  }

  // set for normal operation
  ssrOut(0x0C); // address
  // ssrOut(0x00); // Off
  ssrOut(0x01);  // On
  pulseCS();

}

void writeMAX7219(char address, char data)   {
  if ((address < 1) || (address > 8)) return;
  ssrOut(address); // valid numbers 1-8
  ssrOut(data);
  pulseCS();
}