Hi Donald,

there are several ways to measure resistance and the Wheatstone Bridge was definitively the most awkward way, if a microcontroller should be involved.

The easiest way:
Convert the resistance into a time duration or time relation, since time measuring was an easy and lovely job on any microcontroller.

E.g. the good old SN74121 can do this job very accurately.
Also the internal comparator of the AT89C2051 can be used.

But for deeper assistance you must tell more details, e.g. about measuring range, accuracy, time, ...


Peter