1. A location detection circuit, the circuit comprising: a pattern detection circuit operable to identify a subset of a series of data samples corresponding to a defined pattern, and to indicate a location of the identified subset of the series of data samples, wherein the series of data samples corresponds to a spiral pattern; a computation circuit operable to sum a value of each sample of the subset of the series of data samples to yield a sum; and a center determination circuit operable to identify a location of the spiral pattern using the sum.