12 bits of sweet resolution

Projects Discussion and Showcase Science and Measurement
5

Instead of all this in setup()

pinMode(DATAOUT, OUTPUT);
pinMode(DATAIN, INPUT);
pinMode(SPICLOCK, OUTPUT);
pinMode(SELPIN, OUTPUT);

digitalWrite(SELPIN, HIGH);
digitalWrite(DATAOUT, LOW);
digitalWrite(SPICLOCK, LOW);

you would only have

pinMode(SELPIN, OUTPUT);
SPI.begin();
(and whatever the command is to set the SPI clock divisor to 16 - see the SPI libray page)