I got (am getting) an MPX10DP in the mail as a free sample from Freescale.
I am a little confused by it, so here goes....
What is a simply way to hook it up to the Arduino?
I assume that one air port is a reference, and the other is for a different pressure. If I were to get a long tube and cut it so that one end drapes down to the floor, and one end is 10ft higher, could the sensor tell me how much higher up that tube is from the other?
It says "Differential Pressure Range" is 10 kPa, why is this so low? If that is the case, wouldn't it break under hardly any pressure? That is only about 1.5PSI
You COULD connect it directly to one of the analog pins of the arduino. the way I read the spec and calculate, the full range of the pressure sensor (35mV) would span about 30 counts of the analogRead value, if you use the internal 1.1V voltage reference. You'd get better accuracy with an additional amplifier in there...
The pressure sensor measures the difference in pressure between the two ports. I don't know if your tube example would work, because the air in the tube itself continues to have mass and exert pressure. It looks like Atmospheric pressure is about 7PSI for a mile (one mile altitude has half of standard pressure), so sensor isn't a good altimeter, but it might be a useful barometer with one end sealed to a reservoir at a known reference pressure.
Different ranges of pressure sensors have different applications. Like I said, this one might make a good barometer, breathing monitor, or a "suck and puff" interface for the handicapped (breath pressure is quite low), or sensing increased internal pressure (or lack thereof) due to fan failure in equipment, or low-pressure natural gas pipes (like leading to your stove) (which are quite low in pressure as well, apparently.) For an altimeter, you'd want a larger range (depending on the range of altitude.) For a depth meter (SUBA, etc) you'd want one with a much larger range. For measuring the chamber pressure of your rocket motor, still larger.
According to the datasheet, it shouldn't break till you hit 75kPa...
I suppose I could use it in my PC to figure out what the case pressure is compared to the outside pressure. I could probably figure out some uses....
Do you think this sensor would play nice with a little bit of water? I saw a similar project where the Arduino would say how much water was in a tank. Maybe I could get a popcorn bowl and fill it with water or something.
As for reading it, what do you mean by 1.1 voltage reference? Should I push 5V through it or 3.3?
Also, as for hooking it up,
GND is easy, no issues there...
What are +Vout, -Vin, and +Vs?
Where will I apply voltage? I take it I will be reading from one of the Vout pins?