David Schmidt wrote:
>
> Well, now that the weather is starting to look neat around here,
> I am once again trying to put my weather station together.
>   I have a Motorola MPX5100A sensor (Temp compensated, calibrated,
> conditioned sensor) that outputs 0.5- 4.5V for 0-15PSI.  Since
> atmospheric pressure is around 14.6 PSI, the output voltage from
> this sensor will only sweep a small range for a 29"- 31" pressure
> change (4.2 - 4.7V)
>   Can I use a differential serial ADC like the National ADC0831
> and feed it the output of the pressure sensor and hold the V-
> input at 4.2V?  Or is that too tight of a range (4.2 - 4.7V) for
> a full 8 bit count?
> Thanks
> Dave

 I don't know if your sensor cames with an anti aliasing filter and
sample and hold circuit, you will have to see the data sheets in order
to know if you have to design one (low pass filter with cutoff about
10Hz for pressure proposes). As for the ADC a good method is subtracting
4.2 V to your signal and then amplifie it by 10.

P.S. : Did not see the data sheets!!!

Jorge.
-My own opinions-