Airspeed from MPX5500DP differential pressure sensor using a PIC16F88

[marcusvm]

Hey All,
I am working on a project to calculate the airspeed from a pitot tube that is connected to a differential pressure sensor (MPX5500DP) and then output it to an LCD screen (44780 Driver) using a PIC16F88. I have very little background in picbasic and I am having a hard time writing the code.

To calculate the velocity from the pressure, I want to use the equation

Airspeed = sqrt(2P/1.2) where 1.2 is the density of air

But, the problem is I need P from my sensor. How would I go about getting this value?

The basic setup is I have the Vout from the sensor going through a non-inverting amplifier (LM741C). So the amplified voltage values range from something like 9V to 13V, depending on what the pressure is on the sensor. I know that I need to turn on the A/D conversion and right justify to get 10-bit results, but I am stuck after that. How do I write the code to take the voltage coming in to the pic and turn that into a value for pressure. I've read several other threads involving pressure sensors but none of them were differential pressure sensors.

My current code is very short, but its all I could manage to get together from my research.


'Identify and set the internal oscillator clock speed (required for PIC16F88)
Define OSC8
OSCCON.4=1
OSCCON.5=1
OSCCON.6=1

'Set Up A/D Conversion
TRISA = %11000000 'sets RA6 and RA7 as inputs and the rest as outputs
ADCON1.7 = 1 'Right justify for 10-bit results
Pause 500 'Wait .5 seconds for warm up


I've attached a wiring diagram of how I would like to wire this set up.

Any help would be greatly appreciated. Let me know if I need to provide more information. Again, I am not very familiar with picbasic so the more simple it is, the better.

Thanks!

-Marcus