By the way, instead of using a 2 v reference, use a 2.048 v reference
and then each "step" will be .001 volt. This simplifies any math
that you have to do later.

Other useful reference values are: 2.56 v, 4.096 v, and 5.12 v.

Certain types of conversion steps can also be simplified by choosing the
reference voltage carefully. In effect you are doing part of the
overall conversion at the analog stage instead of the digital stage.

In general, choose a reference value that makes each "step" value
a "nice" number.

Fr. Tom McGahee

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