Airspeed Sensor

This page describes how to set up and configure the SDP33 airspeed sensor

Airspeed sensors are mostly used when operating fixed-wing UAVs to assess the relative speed of the airflow around the aircraft, thus making possible to calculate the aircraft's indicated airspeed.

For this reason it is necessary to ensure that the right airframe configuration has been chosen, otherwise the airspeed sensor would not be available to us via AMC.

Wiring up the Sensor to Skynode

You will need the following components:

• 1x Airspeed Sensor SDP33

• 1x Cable PRIMARY

• 1x Cable Pixhawk 4-pin or the cable that came with the Airspeed sensor

• 1x Pixhawk Adapter Board

1. Connect Skynode to the Pixhawk adapter board using the Primary/Secondary 40 pin molex cables. If you need to use both side of the board you have to connect both 40 pin connectors (Primary AND Secondary) to Skynode.

2. Connect the Airspeed sensor to the Pixhawk adapter board using the dedicated connectors (I2C 2/J28 or I2C 1/J18)

Configuring and Calibrating the Sensor

In this section the following steps will be explained in more detail:

• Power Skynode

• Connect to it via USB-C or Wi-Fi

• Open Auterion Mission Control and enable the Advanced Mode

• Navigate to the "Parameters" tab and change the parameter SENS_EN_SDP3X to 1

• Calibrate your sensor following the public PX4 docs

Step-by-step guide

1. Connect Skynode to AMC via USB-C for example and power up Skynode

2. Access the AMC "Advanced Mode" by clicking five times on the AMC icon on the top left side of the screen. At this point the following Pop-up window should appear on your screen. Choose "Switch to Advanced". Once the change has taken place, the icon should change appearance from the normal orange color, to a transparent one.

5. Click on the AMC icon to get access to the menu. Inside the "Vehicle Setup" continue to Airframe and pick a fixed wing configuration, for example "Flying wing". Apply the changes and restart Skynode.

6. Access again the "Vehicle Setup" menu with AMC in Advanced mode. Scroll down until you see two cog wheels and click on "Parameters". Click on "Sensors", and Look for the SENS_EN_SDP3X parameter and enable it. Now restart Skynode again.

7. At this point Skynode should be correctly configured and the Airspeed Sensor should be available. In order to check that the sensor performs properly access AMC "Advanced Mode" once more. Open the Menu and go to "Sensors", now "Airspeed" should be displayed at the bottom of the list (see image below).

8. Now perform the calibration of the Airspeed sensor. Once finished the sensor should turn green and it should be ready to be implemented on your UAV.