Floating point math

[Glenn]

Now I have rushed into something that I dont know how it works again.

I trying to build something that reads the voltage from a sensor, I connected the sensor as in the datasheet with correct capacitors and connected Vs to the same +5v as the PIC, then I connected the output from the sensor to an ADC input of a 16F877A and reads it with ADCIN.

This works fine, and I get a value that varys between 11 and 90. (When just outputting it to an LCD)

BUT, now I want to know what the real value is, not this representation of the actual voltage.

In the datasheet of the sensor it says:

Vout = Vs*(0.00363*P + 0.04)

..Wich would be (with a little help from my friends, I suck at math)

P = ((Vout/Vs)-0.04)/0.00396

But then I first need the actual voltage, how do I get that ? what kid of value do I get from ADCIN ?

..And How do I use the formula in PBP ? its floating point.. how can I use it to get the value of P on my LCD ?


..I tried to read the PBP manual but cannot find anything, but maybe this is more of a math problem than a PBP problem ?