3DR ArduCopter Hexa B

Cable to debug FMU UART1: DF13 15



To build the 3DR Hex frame follow these instructions. The numbering of the motors by PX4 is consistent with the one of Ardupilot and 3DR.

Note that the 5V power supply from the ESCs is not needed since the PX4IO has its one voltage regulator. Additionally the PX4IO will measure and report the Lipo voltage (software support pending at the moment).

Therefore solder the power cable which comes with the PX4IO directly onto the cables coming from the battery as shown below.

Before plugging in the battery, make sure the polarity of the cable connecting the power distribution board and the PX4IO is correct as shown here.

Note that I used some hot glue to prevent the thin cables from wearing.

Also, I used XT60 instead of deans but I don't recommend it. Firstly they are harder to solder and secondly they need more space, so really there please stay with deans for the power distribution board. To connect to the lipo, XT60 is of course fine.

Below is an overview about my wiring, for details check the manuals of the PX4FMU and PX4IO.

Connected to the PX4FMU:

  • Buzzer
  • GPS

Connected to the PX4IO:

  • 3DR Radio (to FMU UART 2)
  • Arm Switch
  • Power cord from battery/power distribution board
  • PWM output servo signals
  • PPM input

As my Turnigy receiver does not output a PPM signal, I need to use an PPM Encoder.

I've used double sided tape to fix my receiver and PPM encoder onto the bottom layer. The results have been considerably better when the PX4FMU and PX4IO are mounted higher up in order to avoid the electromagnetic interference from the motor/esc wiring as much as possible.

I suggest to mount the PX4FMU as shown in the picture below. Even though it's not in the middle, this has several advantages: the sensor side of the FMU is actually in the middle of the Hex and the Micro-SD, as well as the USB plug, can be accessed comfortably.

Lastly it's time to fix the GPS, 3DR radio and also the arm button.

I mounted the Buzzer beneath the Hex so that I can hear it when the Hex is up in the air.


I'm using the simonk firmware. To flash the simonk firmware on the 3DR ESCs follow these instructions.

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