Pitot tube is coming to INAV

One of the things that INAV was missing, was a decent support for Pitot tubes, or more generally speaking, airspeed sensors. Autonomous flight, or landing, without knowledge about airspeed can easily lead to a stall. Stall can lead to crash. A crash leads to rebuild. Rebuild of big airplane is a nightmare. Although, for some time now INAV was able to use digital PX4 Airspeed Sensors (I2C, based on MS4525), but they are quite expensive and airspeed was only reported in blackbox logs. Not very useful, right?

Now, this is changing. Next release of INAV (1.8 probably) will bring at least support for much cheaper, analog, APM Airspeed Sensor based on MPXV7002 chip. Although some simple additional electronics (2 resistors to be precise) will be required, but this pitot tube should be available for all flight controllers with free ADC input (Current or RSSI). Fancy ADC remapping will allow to use any ADC without built in dividers (Vbat has dividers so can not be used) as pitot input.

mpxv7002 pitot tube for INAV

More than that, INAV 1.8 will (or at least should) bring PID scaling according to airspeed for fixed wings. This should result in better handling on both low and high speed.

mpxv7002 pitot tube for INAV

As you can see on the picture above, APM Airspeed Sensor is already installed on my small flying wing and is waiting for first flight tests this weekend. Logging only for now…

10 thoughts to “Pitot tube is coming to INAV”

  1. Hi
    Is there any easy way to test if the pitot is working from the Configurator? Or do i have to wire up the osd output?
    I couldn’t see anything related to the pitot in any of the tabs.

    I’m currently putting together a Airbot Omni F4 pro V3 with the white pixhawk i2c/digital pitot.

      1. Well that sucks.

        I have 3 i2c errors when i boot up my fc. And im pondering if its the pitot.
        As the pitot is showing up red in the top right, just like a gps does if its disconnected.

        Ill wire up a vtx quickly i guess so i can test it.

        A bit of a oversight that the gui isn’t showing the pitot under the sensors tab.

  2. It is but 2 things. One the voltage return is reversed, and the charts reflect a rise in voltage. Second, the lousy drawing in the data sheet kind of implies by the drawing of the diaphragm that the top tube may press on the response from airflow may be different if swapped. It just looks like the diaphragm was designed to have forward force in one direction and that the reference side had different mechanics.

  3. In messing with these I also found they are very directional. Low airspeed and high angles of attack looses air in the pito reflecting a lower then actual indicated speed.

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