Power Monitoring



  • We are using your VOXL Flight Deck with a Mauch Electronic PL 2X 200A PDB power module (https://www.mauch-electronic.com/pl-2x-200a-pdb).

    How can we monitor the power using the Flight Deck?


  • Dev Team

    Hi @berrios1 ,

    It's likely that unit is using analog output, the Flight Deck contains a Flight Core, which interfaces to via I2C to the VOXL Power Module v3.

    There's no direct analog input into the FlightCore, so you'd need to use something that can talk over a bus.

    Could you run the VOXL Power Module off your VBat? Don't use it pass through to the ESC, but you can still use it to power the VOXL Flight, and using the default cable, you'd get VBat from the VOXL Power Module.



  • Hello @modaltb,

    Thank you for getting back to me so quickly. I will look into that.

    In the meantime, can I power the flight deck and monitor the power using the input power port of the flight deck and port 7 of the PDB (https://www.mauch-electronic.com/pl-2x-200a-pdb).

    Port 7 of PDB: "To flight controller (+/+/I/U/-/-) with Molex Click-Mate 1.25mm / 6p"

    If so, is there a cable for that?

    The datasheet says the Flight Deck uses Power Module v2 (https://docs.modalai.com/voxl-flight-deck-datasheet-connectors/) is the data sheet correct?


  • Dev Team

    Thanks I just fixed the typo on the docs, it should be v3 (the v2 works, we don't make it anymore though).

    I'd say 'no' to powering the VOXL off that though..

    It claims "5.3V / 3A power supply for Flight Controller"

    We need a steady 5.0VDC, and we need to handle 6A inrush current (which is why the VOXL Power Module exists basically).

    Powering off 3A will not be enough and VOXL will likely not boot.



  • Hello @modaltb,

    Thanks for that info. It looks like we have VOXL Power Module v2. We have the Flight Deck M0019-REV B, can I safely switch the power module to the VOXL Power Module v3?

    After switching to the Power Module v3, and connecting it the Mauch Electronic PL 2X 200A PDB power module, would I be able to monitor the power?


  • Dev Team

    Sorry to confuse, the V2 works fine as well. It has a DC jack on it as well, that's the main difference.

    Electrically they are very similar:

    https://docs.modalai.com/power-modules/

    The v3 power monitor supports 2S-6S batteries, but does not support hot swapping.
    
    The v2 power monitor supports 2S-5S batteries and hot-swapping batteries with a wall power supply.
    

    How are you connecting the Power Module to the PL 2X 200A PDB? What battery cell setup are you using?

    If the VBatt is in range, than you will be able to measure the VBat. We also do current sensing, but if you aren't routing that current through the VOXL Power Module (e.g. the XT60 output wire), then you will lose current monitoring (likely OK).



  • Hello @modaltb,

    No worries. We are using 6 cells. Based off what we learned from you, we will scrap the Mauch PDB and use the Power Module V3 to supply the motors with the XT60 LIPO battery cable output.

    Do you know what connector will allow the full 90A through the Power Module output?


  • Dev Team

    Our sense resistors aren't capable of measuring that amperage (out of spec for this power module), but the connector would be an XT90 or greater. To get accurate current readings (not sure if that's critical for you or not), then you'd need to rework the power module's and then update some PX4 params.


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