/*
   Example 39.1 - NXP SAA1064 I2C LED Driver IC Demo I
   Demonstrating display of digits
   http://tronixstuff.wordpress.com/tutorials > chapter 39
   John Boxall July 2011 | CC by-sa-nc
  */

 #include "Wire.h" // enable I2C bus

 byte saa1064 = 56; // define the I2C bus address for our SAA1064 (pin 1 to GND)

 int digits[16]={63, 6, 91, 79, 102, 109, 125,7, 127, 111, 119, 124, 57, 94, 121, 113};
 // these are the byte representations of pins required to display each digit 0~9 then A~F

 void setup()
 {
   Wire.begin(); // start up I2C bus
   delay(500);
   initDisplay();
 }

 void initDisplay()
 // turns on dynamic mode and adjusts segment current to 12mA
 {
   Wire.beginTransmission(saa1064);
   Wire.write((uint8_t)B00000000); // this is the instruction byte.  Zero means the next byte is the control byte
   Wire.write((uint8_t)B01000111); // control byte (dynamic mode on, digits 1+3 on, digits 2+4 on, 12mA segment current
   Wire.endTransmission();
 }

 void displayDigits()
 // show all digits 0~9, A~F on all digits of display
 {
   for (int z=0; z<16; z++)
   {
     Wire.beginTransmission(saa1064);
     Wire.write(1); // instruction byte - first digit to control is 1 (right hand side)
     Wire.write(digits[z]); // digit 1 (RHS)
     Wire.write(digits[z]); // digit 2
     Wire.write(digits[z]); // digit 3
     Wire.write(digits[z]); // digit 4 (LHS)
     Wire.endTransmission();
     delay(500);
   } 

  // now repeat but with decimal point 

  for (int z=0; z<16; z++)
   {
     Wire.beginTransmission(saa1064);
     Wire.write(1); // instruction byte - first digit to control is 1 (right hand side)
     Wire.write(digits[z]+128); // digit 1 (RHS)
     Wire.write(digits[z]+128); // digit 2
     Wire.write(digits[z]+128); // digit 3
     Wire.write(digits[z]+128); // digit 4 (LHS)
     Wire.endTransmission();
     delay(500);
   }
 }

 void clearDisplay()
 // clears all digits
 {
   Wire.beginTransmission(saa1064);
   Wire.write((uint8_t)1); // instruction byte - first digit to control is 1 (right hand side)
   Wire.write((uint8_t)0); // digit 1 (RHS)
   Wire.write((uint8_t)0); // digit 2
   Wire.write((uint8_t)0); // digit 3
   Wire.write((uint8_t)0); // digit 4 (LHS)
   Wire.endTransmission();
 }

 void loop()
 {
   displayDigits();
   clearDisplay();
   delay(1000);
 }