Varying voltage with Arduino Uno

Projects General Guidance
1

I am trying to create a variable voltage to power a phase shifter using an Arduino Duo. I have an 8-bit DAC (data sheet: http://www.mouser.com/ds/2/405/snas539a-214020.pdf) but I don't know how to interface the DAC and the Arduino. Any help would be much appreciated.

2

Connect 8 outputs to the 8 Ax inputs, just like Figure 7 on page 8.
The outputs can be the outputs of a shift register as well if you want to save a few IO pins.

3

How can I control the voltage coming out? What kind of algorithm should I use? I've never programmed Arduinos before.

4

How can I control the voltage coming out?

You set the outputs high & low. 00000000 will be lowest voltage, 11111111 will be the highest, determined by what you have on Vref.

What kind of algorithm should I use?

Don't know - are you after a static DC level? Something else?

I've never programmed Arduinos before.

Start on the Learning page, simple method would just be eight
digitalWrite(pinX, HIGH); /or LOW
to the 8 output pins.

void setup(){
pinMode (2, OUTPUT);
pinMode (3, OUTPUT);
pinMode (4, OUTPUT);
pinMode (5, OUTPUT);
pinMode (6, OUTPUT);
pinMode (7, OUTPUT);
pinMode (8, OUTPUT);
pinMode (9, OUTPUT);
}
void loop(){
digitalWrite (2, LOW);
digitalWrite (3, HIGH);
digitalWrite (4, LOW);
digitalWrite (5, HIGH);
digitalWrite (6, LOW);
digitalWrite (7, HIGH);
digitalWrite (8, LOW);
digitalWrite (9, HIGH);

}

this would output 01010101 on pins 2-3-4-5-6-7-8-9 for example.
Dirt simple, and not very useful. Read & experiment.