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Lab 12 Motors and Controls pt.2

Overview

In this lab, my team and I focused on setting up and calibrating the avionics, motors, and control systems used in the Believer aircraft. We began by calibrating our DATX controller, checking its inputs and outputs, and making sure the correct parameters were enabled in the hardware and LUA script. After that, we built an avionics mock-up by connecting all sensors to the Cube, viewing the system health inside GCS, and documenting our parameter tables for RCMAP and SERVO functions. Once the avionics were working properly, we continued by setting up our motors and ESCs, performing a full ESC calibration, testing throttle functionality, and updating the wiring diagram to reflect the correct servo-rail layout. Completing this lab helped us understand how important calibration, system mapping, and correct wiring are for safe, stable aircraft operation.

Resources

We used several references throughout the lab, including the ArduPilot Complete Parameter List, the ES3054 servo documentation, AT55A ESC guide, AT3520 motor specs, the TBS Tracer Micro TX guide, the Cube Wiring Quick Start reference, and the Choosing Servo Functions documentation. These resources helped us navigate parameter settings, wiring connections, and calibration steps.

Team 6 Members: Clayton Brown, Isabella Avedician, Kenzie Florkiewicz, Diego Hernandez, and Nico Jaekle.

DATX Setup

To begin the lab, we powered on the DATX controller and moved the sticks around to see how the system was responding. The onscreen stick indicators did not match our physical inputs, which told us immediately that the controller needed to be calibrated. We opened the hardware menu and performed the full stick calibration. Once it was complete, the indicators aligned correctly, and we were able to confirm that our inputs were accurate and centered.

After that, we navigated to the LUA script to continue the setup. At first, the “Tracer Nano RX” option was missing, which meant the receiver had not been bound properly. We fixed this by binding the RX through the “Tracer Micro TX” option, which caused the Nano RX menu to appear. Inside the Output Map section, we changed Channel 1 to SBUS and captured an image for our instructor.

During this process, we also reviewed two main concepts we needed to understand for the lab:

Key Takeaways from the DATX Setup:

SBUS vs CRSF: SBUS is an older, one-way protocol that is still widely compatible, while CRSF is a faster, two-way communication system used in modern UAS.

Multi-Bind: This feature allows a single receiver to remain bound to multiple transmitters through a shared cloud ID, so re-binding is not needed.

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Avionics Setup

Once the DATX was configured correctly, we moved into the avionics portion of the lab. We connected all sensors to the Cube, powered the system, and checked the Platform Health Status using GCS. Everything appeared as expected—the GPS, Pitot, RC link, and other components were being read correctly by the Cube.

With the avionics powered, we recorded our RCMAP parameter table, which shows how transmitter inputs map to roll, pitch, yaw, throttle, flaps, and brakes. We also documented the SERVO function table so we could clearly see how the Cube assigns outputs to the flaperons, V-tail servos, rudder, and throttle ports. After verifying these values, we connected the DATX controller and confirmed that GCS recognized the radio link.

Checking the Live Data tab allowed us to observe how the servos reacted to our stick inputs. In stabilized mode, we noticed that the Cube added corrections—rolling caused the rudder to move along with the flaperons. In manual mode, none of those corrections appeared, and the servos only moved when we commanded them. We also noted that the throttle remained inactive unless the aircraft was armed, which is an important safety function built into ArduPilot.

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Motor and Control Setup

After verifying that our avionics behaved correctly, we began working with the motors, ESCs, and servos. We gathered our components and connected a servo and an ESC to the appropriate channels based on the SERVO function table. When we tried to move the servo initially, it didn’t respond. We learned that this was because the Cube does not internally power the servo rail, meaning the servos cannot operate until the rail is powered by an ESC, BEC, or another external source.

To move forward, we mounted the ESC on the thrust stand and applied power with a 6S LiPo battery. We increased current slowly to make sure no potential difference existed. Once the ESC powered up, it back-fed the servo rail and caused the entire Cube system to turn on, including GPS, Pitot tube, and the RC antenna.

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We used the AT55A calibration guide to perform a full ESC calibration, keeping the aircraft in manual mode and armed as required. After the calibration was confirmed by our instructor, we gently ramped the throttle to 100% and verified that the motor ran smoothly and consistently.

One important thing we learned during this part of the lab is how the Cube handles power loss. The flight controller has built-in diode protections that allow it to receive backup power even if the main rail loses power. This means the aircraft can still be flown manually in an emergency, although secondary systems like GPS may not function. This “fly-by-wire-only” emergency mode helps prevent crashes during power failures.

Power Sources We Identified for Each System:

Servos can be powered by a LiPo battery using a 5V BEC converter.

Motors receive power directly from the LiPo through the ESC.

The Cube can be powered through the servo rail, ESC, or a dedicated 5V regulator.

Wiring Diagram

After completing all setup and calibration tasks, we updated our team’s Believer wiring diagram to reflect the correct servo-rail configuration based on the RCMAP and SERVO function tables. This ensures that when we wire the real aircraft, everything will be connected to the right ports.

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Summary

In this lab, we focused on powering, arming, and ensuring proper communication among the Believer’s system components. We successfully calibrated the DATX controller, set up the avionics system, verified sensor connectivity, created accurate parameter tables, mapped our control inputs to servo outputs, and performed a complete ESC calibration. We also learned how power flows through the Cube and how failsafes protect the aircraft during emergencies. Completing this lab moved us one step closer to having a fully functional and safely configured Believer aircraft.

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