I have a time varying pressure sensor output signal from which I would like to obtain the cyclic frequency. The signal originates from a reciprocating gas compressor therefore the voltage signal is a smooth and slightly distorted sine wave, frequency varies slowly from 0-10Hz, but is generally in a steady-state.
The sensor signal is 0-10Vdc, the amplitude is around 0.5V and the dc offset can be anywhere from 0.5 to 9.5v.
I would like to translate the small sine signal into a logic level square wave signal to be received by a microprocessor board (Arduino Uno) for frequency counting.
The approach that I'm thinking of is to shift the ac signal mean to 2.5Vdc, amplify the wave and feed through a Schmitt trigger (I have SN74HC14N)comparator.
I'm sure that this is a very common situation but I haven't found a book chapter to spell it out for the electronics novice.