I've used the second method to measure tilt with a capacitive tilt meter and
it
worked nicely.  Can't say how it would do with the humidity sensor, but the
technique works fine.  I take 128 samples and throw away the lowest few
bits.

Andy

I am also working on a capactive tilt meter, with the same idea as yours -
don't know what sensors you use - AOSI?

Anyway, I think you get better temp stabilization with the bridge, since
with the 555/RC method the R component is influenced by temperature.
However, in my application the device will be used in a temperature
stabilized room, that way it won't matter that much.

Tom