Since Myxa/Télega already has to measure the individual phase currents for the control algorithms, is there a way to query these (or an RMS value) over USB/UART/CAN?
You can query the voltage and current in the DQ system using the status message:
To get RMS, divide by the square root of two.
FYI, this interface is tentative. Kucher and the current ad-hoc proprietary binary interface will be replaced with UAVCAN-over-serial in the next firmware release. We are currently building a new UAVCAN GUI called Yukon that will replace Kucher: