Difference between analog and digital airspeed sensor

ArduPlane Plane 3.4
1

What is the real difference between the analog airspeed sensor
https://store.3drobotics.com/products/airspeed-kit-with-mpxv7002dp
and the newer digital airspeed sensor
https://store.3drobotics.com/products/pixhawk-airspeed-sensor-kit

I askt, because i have some troubles on getting the digital airspeed sensor running on the i2c splitter. Maybe I just switch to the manual sensor.

What is the resolution difference in m/s between those 2 sensors?

2

The digital one is much better than the analog one, apparently. I haven’t used it. The analog one suffers from noise issues, I’d did use that one in the past but found plane worked better without it. But that was quite some time ago.

I’d suggest solving the issue with the i2c one you have.

3

I have tried both and the Digital is much better. In my opinion the analog one is a waist of money.

The Pixhawk with EKF and the latest firmware does an excellent jog of computing airspeed. I don’t install an airspeed sensor unless I am going to use autoland. Most of the time I fly from a small strip where autoland won’t work anyway.

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4

Just adding my 2cents :slight_smile:
Analogue is rubbish. Use digital only.
Thanks, Grant.

5

Just to add to the chorus - go digital if you can. I have two identical aircraft, one with analog, one with digital. The digital gives a much more consistent and reliable reading.

However, if you are stuck with analog, a few tips that can help:

  • Make sure you have calibrated your airspeed sensor at least once using the ARSPD_AUTOCAL function
  • Zero airspeed readings before takeoff by using the PREFLIGHT_CALIBRATION function in mission planner. Loosely cover your airspeed sensor when doing this (I use a piece of loose fitting heat shrink tube) to prevent wind affecting it.
  • Set target speed conservatively high when using autonomous airspeed control (eg. if your plane stalls at 10m/s , never set the target airspeed below about 13m/s in auto modes).
6

Well I would like to stick up for the old Analog sensor with MPXV7002DP differntial pressure IC. It is half the price of the digital one and works well enough , however I am not sure that it is compatible with Pixhawk, but that doesnt mean it is no good!

regards
Andy

7

The analog works fine on the Pixhawk. I find the analog sensor to be adequate. I only have one digital sensor and it’s performance hasn’t motivated me to replace my analog ones.

8

I’ve had good results with the analog sensor on both APM and Pixhawk.

This was a couple flights from last year with a very consistent and accurate reading -
youtube.com/watch?v=uvEsxWSoDtY

Plane now has a Pixhawk and the sensor is still working well.

9

yes, I’ve been flying with analog sensors since they came out - I think even on APM1 , and until Pixhawk came out.
They are absolutely adequate.
Those who experience a problem with some IAS deviation, are most likely requesting a airspeed too close to stallspeed anyway.