Syntax error in the controller?

[adaldo]

When

rosrun crazyflie_controller controller.cpp

I get

line 9: syntax error near unexpected token `('
line 9: `double get('

[whoenig]

You can only rosrun executables, not source files. Try
rosrun crazyflie_controller controller

[adaldo]

When

rosrun crazyflie_controller controller

I get

[rosrun] Couldn't find executable named controller below /home/adaldo/catkin_ws/src/crazyflie_ros/crazyflie_controller

(To compile my project I catkin build and then I source /devel/setup.bash.)

However, I found out that if I

roslaunch crazyflie_controller crazyflie2.launch frame:="body"

then the controller node starts.

[whoenig]

The executable name is actually crazyflie_controller as well, so try
rosrun crazyflie_controller crazyflie_controller
The recommended usage is using launch files though, since this simplifies setting parameters etc.

[adaldo]

How did I miss that!
Thank you so much.

[gitsr-sys]

Hi, @adaldo and @whoenig, I have a programming question about this issue.
Actually, I am a beginner, so it will be very thankful if you explain specifically.

I looked over hover_vicon.launch file, and found the line that file="$(find crazyflie_controller)/launch/crazyflie2.launch".
Also, when I looked over the crazyflie2.launch file in crazyflie_controller/launch folder, I found that the line
< node name="controller" pkg="crazyflie_controller" type="crazyflie_controller" output="screen" >.
However, I do not understand this line, because there is no crazyflie_controller file in crazyflie_controller/src folder, but controller.cpp file...
Even I cannot find crazyflie_controller file at all.

Could you explain about it?

Thank you in advance.

[whoenig]

crazyflie_controller refers to the package name and not a file name. The package name is (just in this case) identical to the folder name.

[gitsr-sys]

Thank you for your reply, @whoenig .
In fact, the text editor did not show "the line" what I attached.
The line in crazyflie2.launch file is the following
< node name="controller" pkg="crazyflie_controller" type="crazyflie_controller" output="screen" >

According to this line, I think the package name is defined in "pkg", so package name is what you said, crazyflie_controller.
But, it also said type has the same name with pkg name....
That is, type is defined as "crazyflie_controller".
This is what I do not understand... the file "crazyflie_controller" does not exist...but controller.cpp exists in crazyflie_controller package...
Could you please explain about it for me?

Thank you.

[whoenig]

This refers to the name of the executable defined here.

[netkimjh]

Thank you for clear explanation.

But, I leant from tutorial that they use it like the following
add_executable(controller src/controller.cpp).
Then, you can use
< node name="controller" pkg="crazyflie_controller" type="controller" output="screen" >

I am curious if you have any special reason for changing the name.
If there is no reason, then just ignore my question...

Thank you anyway.

[whoenig]

No reason.