- use one (digital) pin to select the chip,
- use another to sense when the A/D sampling is finished,
- use a third pin to supply a clock signal to "shift out" the sampling result data, and
Beware that this kind of thing could be headache-inducing for someone new to electronics. REad the bottom part of this post on SPI to get started on that migraine. Or it might be really easy, who knows?