Servos slow to respond

Navio / Edge Getting started
1

I have my new single copter on the bench and I have been testing my setup which is using and FR-Sky V8FR-2 with a Servo to PPM module connected to PPM/SB on the X2 port of the Navio2. Strapped to a Pi3 B.

I’ve set up the flight controller with Mission Planner and calibrated the axis. Connected initially with the WiFi, I then connected using the 433mhz 3DR which is working fine.

For some reason, the servos are very slow to respond. I move the sticks and it can take anything between 750ms and 3 Seconds for the servos to move to the position set.

If I disconnect from Mission Planner then this time goes down to perhaps 500ms, it is still very sluggish and steppy.

Does anyone know what could cause this?

Disconnecting from the telemetry seems to reduce this which makes me think that perhaps it’s try do do something else?

3

Hi Lee,

May I ask you to share the video of this behavior?

Also, could you please disconnect all the hardware except motors and check how they will react on the Motor Test in Mission Planner?

5

I am not using motors, only a single motor (SingleCopter)

I have 4 flight control surfaces (Fins) and they are really slow and steppy even when I use Joystick control in MP, It’s exactly the same.

The Copter has not yet flown. I want to make sure that it is working correctly before I let it fly.

It is sitting on the bench and when I move the sticks, the servos do not move smoothly or in a reasonable time.

Is Navio2 compatible with SingleCopter configuration, FRAME_CLASS 8?

7

How can I share the video? It says it’s too big to upload.

8

The problem with this is that by default a Copter setup has a very high RC_SPEED refresh rate. (250Hz)

This is too fast for the servos and I think something that needs to be addressed in Arducopter firmware for the default setting.
If you reduce this down to 50Hz the issues has gone.

RC_SPEED = 50

1 Like
9

Hi Lee,

Thanks for sharing the solution with us!