Using CC3D as gimbal RC
« on: November 17, 2019, 04:30:53 pm »

If it's not perfectly understood in the title I'm trying to use the CC3D as the controler of the position of a gimbal. (just like "DJI Force pro" or "Freefly MIMIC").

The setup is:
CC3D  -->  Tx (RC from old phantom2)  -->  Rx (from old phantom2)  -->  Gimbal (ronin-s)

1. I managed to connect Rx to the Gimbal, and the RC is working perfectly, controlling Pan, Tilt, Roll, user mode, rec, stop.

2. I took the voltages of the RC joysticks to know the voltages range I need to use.

3. Using the CC3D PWM Output connected to the Tx board a was able to control the move of the gimbal.
Of course, just like the RC joystick, it controls the speed of the movement: through the Servo output PWM it's sending a voltage constantly so it keeps moving (it uses the AttitudeState infos).

4. It means I need these speed information but function of the time --> angular acceleration! So now I'm trying to use the GyroState informations to send it to the Tx.

--> Question: How do I output the GyroState infos of the CC3D to my Tx board.
(The range of tension for the board to respond are: 1.38v to 1.91v, neutral speed being 1.65v)

I'm currently trying to do so with the ReceiverPort of the cc3d in "Outputs+OneShot" mode and modify the TxPID menu but I'm not getting any voltages ouput so far...
Maybe using the MainPort and the telemetry infos is a way?

I hope I'm clear enough, more infos needed to respond my problem?
I'm not sure I did that the right way, any suggestions are welcome of course! :)

« Last Edit: November 18, 2019, 08:51:05 pm by aurelienb »

Re: Using CC3D's as gimbal RC
« Reply #1 on: November 18, 2019, 06:32:32 am »
I'm not sure what you are trying to do.  :)  Tilt the CC3D on the ground and have the gimbal in the air tilt the same?  Using the old phantom transmitter and receiver to do this?

You say that you can use it but you seem to be controlling the speed of gimbal rotation, not the gimbal position.

There are basically two ways to use the CC3D to control a gimbal:

The normal way the CC3D is mounted on the drone.  It is usually controlling the drone and making it fly, but that is not required.  The CC3D can be configured to send POSITION signals to a set of gimbal servos.  It does not have a sensor on the gimbal to actually know if the gimbal is tilted correctly.  It changes this signal from neutral when it knows the drone is not level.  If it knows the drone is a tilting 10 degrees left, then it sends a 10 degree right tilt signal to the gimbal left-right tilt servo.  Think of it like the gimbal servos must be installed with the correct size of output wheel so that it moves the gimbal the correct amount.  There is actually a multiplication adjustment in the setup that does the same thing.

The other way the CC3D can be set up to control a gimbal, the CC3D does not / cannot fly a drone at the same time.  You mount the CC3D on the gimbal so that the CC3D can actually feel how tilted the gimbal is.  The CC3D thinks it is keeping a drone level, but it is actually keeping a gimbal level.  To move the gimbal, you use either brushless gimbal motors with special gimbal ESCs, or you use servos.  You configure the CC3D to be in Attitude mode and adjust the PIDs.  The normal RC inputs to the CC3D can be used to tilt the gimbal and the CC3D thinks it is holding a drone level in Attitude mode and responding to RC inputs to make the drone tilt to fly around.  I will warn you that if you can find the special gimbal ESCs at all, that they are more expensive than it is worth.


If it seems you are just controlling the speed of rotation of the gimbal, then it may be that you have a mixture of these.  You give a small change and it starts moving, but there is no rotation detected, so it keeps moving.  That setup needs the rotation sensor mounted on the gimbal to "feed back" the information that the gimbal moved, and how far.