I was going to start another topic but my query is along the same lines with a 5V pressure sensor instead of flow.
I’ve bought a 5V pressure sensor(http://www.ebay.com/itm/Pressure-transducer-or-sender-100-psi-stainless-steel-for-oil-fuel-air-water-/261260635816)
The A0 is providing 3.3V and I’m picking up 5V from VIN on the breakout at the side of OSPi.
I have a level shifter(https://www.adafruit.com/products/1875) in between OsPi and the pressure sensor.
The few things I am stuck on and cannot find any answers are:
* The above shifter is not i2c safe so does it make any difference as the A0 through A3 are only reading voltage and the PCF8591T is handling the i2c back to the Pi?
* The 5V from the VIN is reading about 4.798V would this affect the end result?
With no pressure(i.e. disconnected) I read 0.46V but when I apply some pressure the reading goes up accordingly so I hope its just a matter of calculating for the voltage difference.
If all of the above makes sense then would that level shifter also help the guys with flow sensor at 5V?