[mluckham]

I would never use floating point calculations in an interrupt service routine - in this case, it is just incrementing counters or subtracting integers to get pulse widths, anyway.

The CPU percentage is around 50%, so it should be quite safe to throw in floating point calculations for the twice-per-second display updates.

I have an accelerometer project with lots of floating point, it works fine.

I haven't found any floating point benchmarks for the Arduino, it will be interesting to try and quantify the difference between FP and integer math operations.