Home › Forums › Hardware › Ospid in perpetual reset loop if BODLEVEL set to 4.3v

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  • rob_lee
    Participant
    May 5, 2013 at 5:48 pm
    Post count: 15
    #3604

    This post stems from a previous one relating to Ospid settings lost/revert to relay operation when powering with internal regulator via 7-30vdc input.

    Help !!

    When using USB power and I set BODLEVEL fuses for 4.3v, Ospid perpetually loops reset, i.e. BOD is activated.

    According to AVRISP MK2 programmer, Target voltage is 4.6v (measured on the ICSP header, I think)

    If I changed to a lab power supply (using the onboard regulator) Target voltage was measured at 4.9v and the device operates correctly with a BODLEVEL of 4v3.

    I’ve looked with a scope and there is almost nothing noise wise on the VCC in either case(certainly not 300mV @ 2us).

    Anyone know which physical pin is used for the BODLEVEL sense ?

    Anyone suggest why it might drop out at 4.6v ?

    Test conditions – main board only (no I/O).

    rocketscream
    Keymaster
    May 28, 2013 at 3:33 pm
    Post count: 65
    #4027

    Hi Rob,

    Are you powering the USB through a hub (where current is limited)?

    The BODLEVEL is being measured internally in the chip.

    rob_lee
    Participant
    June 6, 2013 at 9:25 am
    Post count: 15
    #4028

    It doesn’t make any difference what source I use for the USB power, plug pack, laptop or hub.

    It just doesn’t work when BODLEVEL is set to 4.3V

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