ESC Power



  • After spending several days trying to get my motors to spin, calibrating ESC's, reading a bunch of different posts, etc. I have concluded that you do not either power the "middle" pin across the pwm array nor do you tie the positive pins together so they may be powered by an external source like a BEC. We have 4 Castle ESC's (with one BEC) hooked to 4 motors which all work fine when attached to a pixracer. Only the motor attached to the ESC with a BEC will turn when this array is attached to the flight core. I can surely understand why you don't power the middle pin with the flight core power as hooking a couple of servos to that array would surely burn out any voltage source you could provide, but I don't understand why you don't hook all the middle pins together so that they may be powered by one ESC/BEC as every other flight controller I have used does. Further, I don't understand why that pin even needs power for the ESC's. Basically you are providing a PWM signal versus a common ground for all controlled ports. As long as that signal is above about 1.5 volts, most ESC's should interpret that as a one, and below .5 volts is a zero. I can only assume that ESC's want to know whether the signal range is 3.3 or 5 volts. Either way, unless I jumper the middle pins together, I will have to provide 4 ESC/BEC's to get my motors to run. I obviously am not the first one to notice this problem. Why don't you tie those pins together?


  • Dev Team

    @Jimk_Aero

    Sorry so hear that you're still having problems. The built-in BEC shouldn't be required for basic use case. Unless you're trying to power some other on-board electronics/avionics with the BEC.

    All you should need is the "power in" to all 4 esc's from a PDB and then signal and ground from esc's to flight core J7, via the breakout board.

    Modalai's breakout board was designed for PWM signals only and works well in that regard. Also check to make sure that DSHOT_CONFIG
    is set to "disable"

    Here's some notes from our board designer to clarify.

    The primary design intent was to be used with a distribution board for power

    It is actually unsafe for these types of pin headers to have exposed voltages on them

    We wanted to prevent some customers from accidentally installing two BEC generators on these blocks which occur all the time in other hobbyist forums/kits and customers end up damaging their BEC modules.

    We apologize we did not make it clearer this is just a breakout board and not a BEC distribution block.


Log in to reply