DJI 4114 400kv motors

Having issues getting motor test in Mission Planner to spin the DJI Arms which include built in ESC’s. I’m reading that because DJI uses an opto isolator device in the ESC, there is no need for cal. But yet I connected a Spektrum servo tester where you can control the width of the pulse, and they start spinning at 1180 us. (Micro-seconds). Not sure how to get the motor test in mission planner to work for these DJI Arms I have.

Try set mot_pwm_min, 1180, for normal analog ESC.

Take note the setting of spin minimum and arming values

That’s the issue of proprietary products.

Thank you for your response. What do I need to know about SPIN MIN AND ARMING VALUES?

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But I don’t know if I have a normal ESC. as I stated, the motor and ESC is all one unit.
Also I have read that the DJI ESC uses an opto isolator and that type does not need calibration. Please continue your support in getting my system working.

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Secure Encryption 58.1

Read the doc. Use the MP motor test to determine the values. Slowly increase the throttle % in MP motor test until it start to spin. if you found the deadzone of the ESCs was 7%, set MOT_SPIN_ARM to 0.09 (i.e (7 + 2) / 100).

Can try 1120 - 1920 us

High chance yes, it was used in DJI S900 very old model drone.

Thank you…. Yes I crashed the s900 and saved 4 arms that work. I have increased the % value during motor test up to 19%. Still NO MOTOR SPIN.
I just tried connecting the motor from a new holybro X500 that motor does not spin either.
I don’t think the FMU output is working properly. How can we check the output of the ESC driver?

I set the time to 1800 micro seconds. Still nothing. I also tried connecting a HolyBro X500 ARF that I built, and that motor does not work.

SAT COM V14.2.2
Secure Encryption 58.1

Do you have a hardware safety button/switch installed?
What flight controller are you using? Pixhawk 6C or 6X?

What is your BRD_SAFETY_DEFLT value?

MOT_PWM_MIN, 1180 or 1120

Post the parameter file. If it arms post a link to a .bin log file.

The quad must be armed to perform the motor test?
I have been watching PAINLESS 360 videos on setting up specifically the PixHawk 6C, and up to this point, all has been going well. Again, using a simple Spektrum Servo checker, I apply 24 volts to the motors. I connect to output of servo checker who displays the pulse width in micro seconds .
I increase the pulse width till I get to about 1180 and then the motors turn. If I increase the pulse width to 1900 us, motors are at full speed…
If I can get these DJI units to fire up with a simple servo checker, I know I ain’t to far away. The only thing is 1.
The outputs from the FMU connector is not working or I am plugged into the wrong outputs of the PWM unit. I’m in 1-4
Your help with this puzzle would be greatly appreciated.


P.S. I hate to have to buy 4 Spektrum SMART ESC’s. Just to get it to work.
I guess that I will try all of the ESC types in Parameters menu to see.


No point in that, leave it at PWM (default)

Did you refer to this sample wiring diagram?

If it arms then post a link to the .bin log file downloaded from the Flight Controller.
Downloading logs

I will set the GPS to what you recommend. The BRD_SAFETY_DEFLT. IS 1 enabled.

Dave I appreciate your help with my issue, like yourself, I too was in electronics as a manufacturing test engineer. However that was in the 70’s & 80’s. It’s a little different now that I’m in late 60’s. So your effort in this is most appreciated.
Lots to digest in short time. All I want to do is fly. I have read the link you sent me about logging, but isn’t that for flight time logs? When I pull up PARAMETER LIST its pages and pages and pages. Is there something that I can look at and document that? Or should I be logging my troubleshooting steps?
Thanks lots…. Rick

If you don’t have a hardware safety button or switch, set it to 0 for motor test or use latest MP GUI to trigger it to off.

Personally, I feel your direction is wrong to use open hardware, open source.

Why do you feel I should not proceed the way I am?

All you wanted is to fly a drone. Is like you just want to drive a car and not how to make a reliable car. Just buy any off the shelf drone with some limited customization, maybe.

lol…… I understand, if you were 69 yrs old, retired. You might think a little different.
All I want to do is be able to fly autonomous flights and take photographs.
Are you saying because of the security issue?

Also, the reason is I am looking for a heavy lift workhorse…. Under a lift and test,
I was capable of a dead lift of 16 lbs. that’s why I want to proceed. I’m taking up multi spectral camera, FLIR cameras and LiDAR equipment. Got it?