Cooling solution for VOXLCAM



  • Hello,
    I am using system image version 3.3.0 on VOXLCAM. My issue is regarding VOXLCAM (Snap 821) cores detecting high temperature and PMIC making two cores to shutdown completely. My application needs all four cores to be functional in order to run smoothly. When I observe two cores been shutdown QVIO SLAM algorithm drifts and I also had flight crash. From complete cooldown condition my CPU temperatures are raising to above 90 degree celcius within 5 mins making 2 cores to shutdown.

    I do have VOXL Cooling fan from here along with LTE modem installed. What I understand from VOXLCAM mech design perspective is LTE modem is sitting on top of Snapdragon 821 so installing fan beyond LTE modem might be useless.

    My queries :

    • What should be voxl cooling fan position on VOXLCAM with 5G LTE modem installed? UAV downwash ins't helping in my case for passive cooling.

    • Is there any software solution to prevent this excessive CPU OVERHEAT issue? FYI my application consumes only 1500 MB of RAM in full load condition and avg CPU utilization goes near to 70%.

    • Major problem is QVIO drifting once cores are shutdown. Any fix for this?


  • Dev Team

    Hi,

    We've run into this issue as well when the VOXL-CAM is sitting on a desk, for which we've designed this cooling stand. As for when the cam is in motion on a body, we've only flown it on the seeker where the propwash is enough to keep the unit cool enough to utilize all of the cores fully. The cam unit wasn't designed around that smaller fan, we use that primarily on our other platforms with an open board where we can direct air directly onto the board.

    As for QVIO, we've also seen this behavior when cores shut down, but we try to avoid overheating at all costs, and generally don't carry any expectation for software to continue operating properly once the pmic is shutting down cores.

    Generally, I'd recommend :

    • Trying to make sure that the cam is placed on a spot on your drone with as much airflow as possible
    • Optimizing your code as much as possible to minimize CPU utilization
    • Download the latest software release (3.8.0-0.7) from here since we've spent most of the last year improving and optimizing our services and libraries and there should be significant improvements since 3.3.0 was released

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