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AT 209 - Lab 09 - Believer GCS and Parameters

Overview:

Duirng this lab, we worked with a range of different software tools to connect all the electronics for the believer before we built the believer itself. One of the main challenges we faced was the fact that the flight controller software is open-source, while the system used by Windracers is closed-source. This created a significant obstacle in terms of navigating the software, as we were unable to make certain necessary adjustments or access specific features due to the proprietary nature of the Windracers system. At the end of the lab we were able to complete all of it except the GPS.

GCS:

At the start of the lab, while using an AIDA3 PC, the Cubepilot was connected to the GCS via USB. Shortly thereafter, the connection was verified to be live by monitoring movement in the HUD. The Cubepilot flight controller show the aircraft’s orientation and instrument readouts. After this was assured, some parameters and setting were managed. some such settings are the GUID, connectivity indication, and flight modes. The GUID_THISMAV parameter controls how the system differentiates one vehicle from another across networks or DroneCan buses. Connectivity is confirmed with the green Beating Heart icon toward the top of the screen.

Parameters:

After connectivity was assured, some of the parameters of the GCS were changed. At the beginning of the task, the parameters were first downloaded and saved. This is important when starting up the program, especially since we will be changing these shortly. Also, one point to note is that the telemetry module is how we communicate wirelessly with the flight controller, and it would soon be installed. It is also important to understand that MavLink is a messaging protocol used for communicating between drones and drone components.

Setup of telemetry was fairly simple, and required a few steps. First, the crew connected the air side RFD900 to the Cubepilot TELEM 1 port using the supplied cable. They were sure that the connector orientation was correct on the RDF900 end. Second, with the Cubepilot still connected by USB and in the GCS parameters tab, the crew confirmed the parameters matched SERIALX Parameters. Then we connected the ground side to the PC and changed the connecteion from USB to RFD900. The BAUD rate was kept at 115200, and the serial protocol was kept at “MAVLINK.”

Airspeed:

The airspeed indicator was optional, but highly recommended. If there was no airspeed it the controller and the drone will be on a open-loop throttle rather than a closed one. Open-loop throttle mapping sends preset throttle commands without sensor feedback, unlike closed-loop mapping, which adjusts throttle based on real-time sensor data to maintain desired performance. Airspeed sensors rely on pressure readings from a pitot tube, and that is what was installed later. The pitot tube is long so it can collect information from undisturbed free-stream airflow, where the air pressure reflects the aircraft’s true dynamic pressure. The communication protocol used by the airspeed sensor is I2C Address: 0x28H.

To install the pitot tube, the crew attached the provided silicone tubing to one end of the pitot tube and to the correct port on the airspeed sensor. While using the provided cable, they then connected the airspeed sensor to the Cubepilot in the appropriate port, 3. In the GCS parameters tab, the crew later modified the parameters to match ARSPDX Parameters. Before doing this, they were sure to complete the original column to save a record of original settings. Some parameters are only visible upon reboot. From the Engineering tab, the crew performed an Autopilot Reboot of the board. We had to keep in mind to download all the parameters again.

GPS:

GPS is a very critical tool to use for UAS operations especially like here where the goal is to eventually fly the aircraft above 400 feet AGL. For the believer we used Here3+ GPS. The communication protocol the Here3+ GPS uses is DroneCan 8Mbit/s. We also had an IMU in the GPS unit which included the magnetometer, gyroscope, and accelerometer.

We were able to download the files to the GPS unit, but were unable to connect it properlly. We talked with Professor Rose and he wasn’t also able to get it connected.

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