/**********************************************************
Example program I2C-OSC interface with Arduino.

SETUP:    I2C-OSC => Arduino
          PIN2 => A4, PIN3 => A5, PIN4 => ground, PIN8 => +5V
Note:     The program is written for address 0x2E (Arduino address 0x17).
          This program was tested using Arduino Nano
Document: LTC6904 datasheet
Updated:  September 4, 2008
E-mail:   support@gravitech.us
          Gravitech
(C) Copyright 2008 All Rights Reserved
**********************************************************/

#include <Wire.h> 
 
void setup() 
{ 
  Serial.begin(9600);
  Wire.begin();        // join i2c bus (address optional for master) 
  delay(1000);
} 
 
void loop() 
{ 
  const byte I2C_WR = 0x17;      // I2C write address 
  
  byte DAT0;           // I2C high byte data   
  byte DAT1;           // I2C low byte data 
  byte i;              // Counter 

  for (i=0; i<2; i++)
  {
    if (i==0)
    { 
      /* Set I2C-OSC to 128kHz */
      // Looking at the table on datasheet page 7, we need to set OCT = 6 for 66.5kHz to 132.9kHz
      // Looking at the datasheet on page 6 and calculate DAC value = 984 (0x3D8) for 128kHz
      DAT1 = 0x6F;
      DAT0 = 0x60; // CNF1 = 0 and CNF0 = 0
    }  // end if
    else
    { 
      /* Set I2C-OSC to 256kHz */
      // Looking at the table on datasheet page 7, we need to set OCT = 7 for 133Hz to 265.7kHz
      // Looking at the datasheet on page 6 and calculate DAC value = 984 for 256kHz
      DAT1 = 0x7F;
      DAT0 = 0x60; // CNF1 = 0 and CNF0 = 0
    } // end else
  
    Wire.beginTransmission(I2C_WR);
    Wire.send(DAT1);
    Wire.send(DAT0);
    Wire.endTransmission();
    
    delay (2000);
  } // end for
}