• Maybe the connection is to bad. I don't know the problem well enough, but is this a possible solution?
  • I know this is a very old question but i am kind of in a similar situation. I already have a Pixhawk 2.4.7 and EMAX RS2205 2300kv motors. I was thinking of buying the Emax BLHeli Series 30A ESC(

    Were you able to resolve the issue?
    This link( says that Pixhawk has problems with EMAX ESCs.

    Does anyone have any idea about this??

    I saw Alireza Manzoori 's replay that it has bee resolved for the EMAX Simon ESCs, but what about the model mentioned above?

    Grateful for any help.
    BLHeli Series 30A ESC (ONESHOT available)
    BLHeli Series 30A ESC
  • I have the same problem, but with FVT LittleBee 30A ESCs. I have enabled PWM input in BLHeliSuite, but it still doesn't work. Since these ESCs are made for BLHeli, I don't think they need modification.

    • I have partially solved my problem. If the ESC initially gets a signal, that is equal or slightly higher, than the PPM Min Throttle value set in BLHeli, it won't arm. In Ardupilot you have to set the THR_MIN_PWM slightly below the value, that you set in BLHeli. A 10us difference works fine for me.

      After arming, the motors spin up normally, but if I push up the throttle stick a bit, (depending on the aircrafts attitude) some of the motors shut down, because the PWM value goes to THR_MIN_PWM (instead of THR_MIN_PWM+THR_MIN), which we have set below PPM Min Throttle in BLHeli. At least this is what happens with the hovering ESCs on a QuadPlane. I'll try to search for a solution and maybe open another topic for this particular problem.

  • hi guys, 

    i run into the same trouble ..

    got a brand new px4 and have emax blheli 30a opto  esc. 

    but they want arm. 

    after find this thred, i remove this 2 parts, like aldo from the group recommend. 

    but now, when i push safty button on pixhawk, the esc only do beep, beep, beep, beep, always same tone, no break

    any ideas what it is ? 

    thanks for your knowledge and your help!



  • Thanks guys, it works!

    My ESC is Emax BLHeli 60A, looks slightly different, but I worked out which two bits to remove. Picture attached.


    • Hi, 

      I would like to try the same trick on a BLHeli 12a...but I don't know which are the two bits to be removed...

    • Thanks Piotr, worked like a charm!

  • If you look at the earlier posts you will see there is SMD components that need to be removed, one is a resister and the other is a capacitor. Just heat up the solder either side soldering iron and remove with tweezers.

    I think from memory if you check out the BLHeli flashing guide it tells you which ones to remove so you can flash them. This change also allows it to work with the Pixhawk.


    • Does removing these components have any negative effects on the ESC? 

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