My hex-X has 2, 4-in-1 32-bit ESCs operating on dshot 600 protocol. I have the 3 left-side motors connected to one of the ESCs, and the right-side motors connected to the other. I am running ArduCopter on the FC. I am able to configure the ESCs with BlheliSuite, and can control the ESCs fine. Each ESC has a single serial line that are connected together before going to a serial port on the FC.

I am having difficulty making sense of the telemetry data being displayed on Mission Planner. The same voltage is reported for all motors, which I would expect. However, instead of seeing 22.9 V (6S) as per the multimeter, I am getting 18.4 V. Why is this the case? What options do I have to get accurate voltages?

Also, the currents, RPMs, and voltages appear for 8 motors, even though this is just a hex. Is there anything I can do differently here?

Thanks in advance for any light you may shed.

I have no ArduCopter experience but based on what I know from Betaflight and a bit of iNav:

Betaflight always shows 8 motors on the Betaflight Configurator> Motors tab regardless of whether its a quad, hex or octo - copter. Its the same in iNav. Nothing we can change about this behavior AFAIK besides its not doing any harm is it?

With regards to the voltage reading in Betaflight and iNav we can change the Voltage scaling in the Power & Battery tab. ArduCopter should have something similar.