Ardupilot log messages meaning

I get the following messages on the Ardupilot log right around the moments where the drone starts exhibiting very strange behaviors:

  1. Where are these messages generated? Is this text coming from the Ardupilot code or the Myxas themselves?
  2. What’s the meaning of this “Passive Phase modulation disabled”?

We’re using Myxas with Telega 0.5


The message comes from the motor controller, not from the flight controller. It refers to the transition between two phase voltage modulation strategies shown in the following diagram. The left part shows the regular sinewave modulation, the right part shows the “passive phase” modulation strategy:

Also here’s a very instructive comparison of the two:


The original illustration is made by Max La and published under CC BY-SA 3.0.

Thanks @pavel-kirienko
In pracrice - what does this transition mean for the motor control and why or when does the Myxa descides to transition?

Furthermore - I’m getting some other messages of the same type, where can i find some documentation regarding the meaning of these messages?

This is explained here, in section “vector control system”:

Starting next week, we will advise our customers to adopt Telega v1.0 — the first stable release of the Telega motor control solution that is compatible with the existing hardware. An official announcement will follow. The stable release is equipped with comprehensive documentation available at

While v1 is obviously built on the same core IP as Telega v0, it comes with certain differences. One such difference is the fact that it does not support DroneCAN, focusing exclusively on Cyphal instead. I am familiar with the details of your application and I can predict that you will benefit from the adoption of the new firmware. As an ArduPilot user, however, you will be facing the obvious problem that the following pull request, which brings support for Cyphal-interfaced motor controllers into ArduPilot, is failing to gain attention of the maintainers: