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Throttle vs Forward Channel

What is the difference between Throttle and Forward here?

http://www.ardusub.com/operators-manual/rc-input-and-output.html

Hi @rdehart,

Here, Throttle means Up/Down.

So with Mavlink, when do we use arm vs arm throttle?

The reason I am asking is I would like to send manual PWM commands to the individual motors. I see that OverrideRCIn in mavlink allows for forward or lateral which means pairs of motors are given commands. Is there a way to send individual motors commands?

It looks like I can use DO_SET_SERVO in Mavlink, but I dont have a mapping of which servo is which

Nevermind, it looks like it is here:

http://www.ardusub.com/getting-started/initial-setup.html

But could you confirm I could send manual signals to these via Mavlink?

Can you tell me if you succeed to send through override ?
I’m using mavros and I was forbidden to send through override and using servo command :(.

Im trying to run ROS and talk to each motor individually. It seems that mavros and OverrideRCIn only allow commands to pairs of motors (up, down, left right, but not individuals to do diagonals or rolls). Im not 100% sure about that though.

According to this:

I cant do it to the motors.

So you need to use the cmd_vel then for your case.
I got other channels unassigned that I could use.

Please elaborate. Did you put the ESC connections to the unused PWM connections on the PixHawk to bypass the restriction? I do not see the cmd_vel Mavlink message.

I’m guessing thoses topics :

Subscribed Topics

~setpoint_velocity/cmd_vel_unstamped (geometry_msgs/Twist)

  • Velocity setpoint.

or this one :

~setpoint_attitude/cmd_vel (geometry_msgs/TwistStamped)

  • Send angular velocity.

Thoses two are topics subscribed by mavros (use it to control your ROV)

Thank you, I will try this. What about what you said about the unassigned channels. You moved them to physical ports greater than the PWM out port 6?

Did you move the physical PWM attachments from ports 1-6 or did I misinterpret you?