I have a non-linear sensor with a 0-5v output that I'm trying to combine with a second, identical sensor's output to measure a combined total. The sensors may have significantly different values at times, so I can't average their voltages. I need to add them using a lookup table.

For example, the sensor's output voltage is the square root of the measured quantity (lbf for example). So a measurement of 4 lbs yields a sensor output of 2 volts. 9 lbs = 3 volts, 16 lbs = 4 volts, etc.

So if sensor A reads 2 volts (4 lbs), and sensor B reads 3 volts (9 lbs), the combined voltage output would be 3.6 volts (13 lbs).

Logic:

- Compare sensor A's voltage to the lookup table (2v = 4)
- Compare sensor B's voltage to the lookup table (3v = 9)
- Add the table values (4 + 9) and, using the table, determine the combined voltage (13 = 3.6v)

__not__a convenient equation, so it would need to interpolate between adjacent values (linear interpolation is fine).

How would you recommend creating such an adder? If you can at least point me in the right direction, I'm willing to do the legwork. I'm hoping you can at least save me from going down the wrong path(s) and wasting time. Thanks!

Rel.