UPDATE Feb 11 2017:- An observant viewer spotted a discrepancy between the code in the video and the code attached/published here. I have now updated it to all match.
In the following two videos we look at the use of a TI ADC and DAC TSSOP-16 chips to extend the abilities (Resolution and accuracy) of the Arduino UNO for use with the Power Supply project
First up the ADC - ADS1220
and now the DAC, DAC8574, Oh and some more I2C debugging 
with the MDO3000
Here is the DAC8574 code for those that are interested, sorry for the delay posting
#include <SPI.h>
#include <Wire.h>
#define PGA 1
#define VREF 2.048
#define VFSR VREF/PGA
#define FSR (((long int)1<<23)-1)
//#define DAC8574_ADD 0x98
#define DAC8574_ADD 0x4C // allowing for RW bit being added
#define DAC8574_CTR 0x34 // broadcast to all dac channels
volatile byte MSB;
volatile byte data;
volatile byte LSB;
//volatile char SPI_RX_Buff[3];
volatile byte *SPI_RX_Buff_Ptr;
byte val = 0;
unsigned int Sin_tab[256] = { 32768,33572,34376,35178,35980,36779,37576,38370,39161,39947,40730,41507,42280,
43046,43807,44561,45307,46047,46778,47500,48214,48919,49614,50298,50972,51636,
52287,52927,53555,54171,54773,55362,55938,56499,57047,57579,58097,58600,59087,
59558,60013,60451,60873,61278,61666,62036,62389,62724,63041,63339,63620,63881,
64124,64348,64553,64739,64905,65053,65180,65289,65377,65446,65496,65525,65535,
65525,65496,65446,65377,65289,65180,65053,64905,64739,64553,64348,64124,63881,
63620,63339,63041,62724,62389,62036,61666,61278,60873,60451,60013,59558,59087,
58600,58097,57579,57047,56499,55938,55362,54773,54171,53555,52927,52287,51636,
50972,50298,49614,48919,48214,47500,46778,46047,45307,44561,43807,43046,42280,
41507,40730,39947,39161,38370,37576,36779,35980,35178,34376,33572,32768,31964,
31160,30358,29556,28757,27960,27166,26375,25589,24806,24029,23256,22490,21729,
20975,20229,19489,18758,18036,17322,16617,15922,15238,14564,13900,13249,12609,
11981,11365,10763,10174,9598,9037,8489,7957,7439,6936,6449,5978,5523,5085,4663,
4258,3870,3500,3147,2812,2495,2197,1916,1655,1412,1188,983,797,631,483,356,247,
159,90,40,11,1,11,40,90,159,247,356,483,631,797,983,1188,1412,1655,1916,2197,
2495,2812,3147,3500,3870,4258,4663,5085,5523,5978,6449,6936,7439,7957,8489,9037,
9598,10174,10763,11365,11981,12609,13249,13900,14564,15238,15922,16617,17322,
18036,18758,19489,20229,20975,21729,22490,23256,24029,24806,25589,26375,27166,
27960,28757,29556,30358,31160,31964 };
void setup()
{
Wire.begin(DAC8574_ADD);
}
void loop()
{
SetDAC(0, 0x4000);
SetDAC(1, 0x8000);
SetDAC(2, 0xC000);
SetDAC(3, 0xFFFF);
while (1)
{
for (int x = 0; x<256; x++)
{
SetDAC(0, Sin_tab[x]);
}
}
}
void SetDAC(unsigned int channel, unsigned int value)
{
int DACCmd = 0;
switch (channel)
{
case 0: DACCmd = 0x10; break;
case 1: DACCmd = 0x12; break;
case 2: DACCmd = 0x14; break;
case 3: DACCmd = 0x16; break;
default: break;
}
Wire.beginTransmission(DAC8574_ADD); // transmit to device
Wire.write(DACCmd);
Wire.write(value >> 8);
Wire.write(value); //
Wire.endTransmission(); // stop transmitting
}
