I have an I2C airspeed sensor on my Bixler. Can I use it as a source of altitude information as well as airspeed, instead of using the onboard barometer? My fuselage has weird airflow that is possibly interfering with static pressure readings, but the static ports on my pitot tube are in clean air.
The driver is only set up to handle dynamic pressure difference and temperature from the sensors.
I’ve been looking into this as well and would like to know how we can use the static pressure from airspeed sensor for altitude/baromter measurement. The only accurate way to obtain barometric pressure is via pitot tube static port. Otherwise, set up a static port on your aircraft that is at 90 degree to airflow and mount FC or external barometer there (like so; https://qph.fs.quoracdn.net/main-qimg-c884d8a697540d1b661f37581582c2f3-c)
Foam is included with some flight controllers to place over the barometer. Have you tried anything to suppress the airflow around the barometer?
The pressure sensors used for ASI are differential pressure sensors, and as such they only measure the difference in pressure across the two ports (one static, one with dynamic pressure). You need an absolute type sensor to measure altitude barometrically. Technically you could use an absolute sensor to measure static pressure and another to measure dynamic pressure, then subtract the two. That would get you both altitude and airspeed but you need two sensors. That is likely to run into resolution problems due to differing (optimised) spans between the absolute and differential transducers. The differential sensors are much better at measuring small differences in pressure.