Ok, long story short I'm trying to be cheap and crafty at the same time and have come up with two (possibly three) options for how to handle this. I want a wideband setup for my car, but the car has the $150+ sensor already installed, I have an ouput chart for that sensor and have fit a 3rd order curve to that chart with an R^2 value of .999

So, my desire is to either find a site/book that can teach me how to wire a 3 digit display that will convert the input voltage into the desired output values (using this 3rd order curve), or find somewhere I can buy a cheap computer that would do this.

Input voltage range (in millivolts) is 0-5000, there is a vertical asymptote at 5000 however (not reachable) so the model is off in higher values (unimportant for my use).

The formula of fit is:

Output = 0.0000000004X^3 - 0.000001X^2 + 0.002X + 9.932

Even something "approximate" (within .05-.1 on the output value would be acceptable.

The other options I have are to just use a dial gauge with a 0-5V input range and print a new face with the necessary scale for this. What I would like to do is have the digital display with an LED dial gauge (LED's light the dial with increasing voltage) and have the scale on the dial.

I've taken circuits classes but its been a while, so if anyone has any ideas where to start looking I'd appreciate it.