Interfacing Pressure Sensors to Microchip's Analog Peripherals
Pressure measurement devices can be classified into two groups: those where pressure is the only source of power and those that require electrical excitation. The mechanical style devices that are only excited by pressure, such as bellows, diaphragms, bourdons, tubes or manometers, are usually suitable for purely mechanical systems. With these devices a change in pressure will initiate a mechanical reaction, such as a change in
the position of mechanical arm or the level of liquid in a tube.
This Application Note will concentrate on the signal conditioning path of the piezoresistive sensing element from sensor to microcontroller. It will show how the electrical output of this sensor can be gained, filtered and digitized in order to ready it for the microcontroller?s calibration routines. This theoretical discussion will be followed with a specific pressure sensing design that is specifically designed to measure barometric pressure.