Fix example launch files

[dabakix8]

Hello.

I am trying to start motor with using motor.launch which is provided as an example. But it does not work for me. Actually, I've already checked closed thread #2 and #6, but I am still confusing.

My situation is the follwoings:

1. My PC and ev3 can communicate vis ssh.
2. ultrasonic.launch works. I could see the value from ultrasonic sensor.

I compiled every packages which provided in "Hacks4ROS/h4r_ev3_ctrl " in my PC. So, I am thinking that
it is possible that when I run "roslaunch motors.lauch", "h4r_ev3_manager" in my PC is started.

When I do "rosnode list", I can see "/ev3dev/ev3_manager_node", but the following command does not work.
rostopic pub /ev3dev/OutPortA/command std_msgs/Float64 "data: 5.0"

Do I need to modify "motors.launch" according to my environment? I need a hint.

Thank you.

md

[dabakix8]

Hello.

I resolved it. Actually, it was memtioned in #2, but it was not clear. Concretely, what I did is below.

I deleted the following tag from the exapmle of motor.launch, then it works.

"node pkg="h4r_ev3_manager" type="ev3_manager_node" name="ev3_manager_node" output="screen""
"/node"

I recommend the node tage above should be deleted from the example to avoid misunderstanding.

Thank you.

md

[cyborg-x1]

Oh yeah that's right there are some issues in that one .. it should not start the manager node ...
That's probably left from testing it myself some time ago

[yrosascu]

Hello,

Have you seen the data of your ultrasonic sensor? how did you do ? because I am trying to ,test this sensor and I havent receive any data, Did you do some change in the code?

[dabakix8]

Hello, yrosascu-san

Honesty, it is not clear for me your present situation. You can communicate with ev3 via ssh? If yes, did you launch the provided launch file from your PC? I have not modificed any thing about launch file for ultrasonic.

To receive the data, you need to make one node to see the ultrasonic data. Did you do that? If yes, can I see your code? Launching ultrasonic sensor does not show data.

md

[valerybugakov]

@mdaiba Could share an example of your motor.launch file?
I'm trying to get motors work too using this package. I got Ev3InfraredController working but cannot figure out how to configure motors. If I have only one motor on PortA should I delete all the configuration about other ports and inputs from the config files?

Also how did you figure out how to control motor? Cannot find any info about that.

Thanks!

[valerybugakov]

@cyborg-x1 maybe you could share an example for motor.launch? Would appreciate that.

[cyborg-x1]

Just remove the motor you do not want the controller for in the launchfile.
Here you probably see the connection:
OutPortA is a name freely definable by you. But inside the launchfile it points to the settings in the yaml file:

in motors.yaml
OutPortA:

type: velocity_controllers/JointVelocityController
joint: Joint_A

<node name="controller_spawner" pkg="controller_manager" type="spawner" respawn="false" output="screen" args="OutPortState OutPortA OutPortB "/>

So if you do not need OutportB:

<node name="controller_spawner" pkg="controller_manager" type="spawner" respawn="false" output="screen" args="OutPortState OutPortA "/>

[valerybugakov]

@cyborg-x1 thanks for explanation, is there a place where can I read about it or maybe a code block where it's parsed and used? I've jumped into ROS stuff a month ago, hopefully it's not very dumb questions :)

Btw thanks for the awesome project!

[cyborg-x1]

You are welcome ;-)
You should read about ROS Control - thats the basic ros package/library behind ev3_manager

[yrosascu]

mdaiba,
In my case, I still do not even get the movement of the motors, I guess the problem is the network configuration because it returns this:
Couldn't find an AF_INET address for [ieka]

But I configured it as I have been recommended in the issues, but so far it does not move.
I change hosts files as it says here: ros wiki but nothing.
Maybe do you have any idea?

Thanks for you help.

[cyborg-x1]

Best thing to check first if you can rostopic pub and echo in both directions
Brick <-> PC
AF_INET sounds a bit like DNS errors and you have to set ROS_IP, for ROS I recommend having a DNS runnning, cause even if ROS_IP is set, your IP can change each time you connect to the network which would require updating ROS_IP again and again.
Get a router with OpenWRT or install a DHCP/DNS on one PC of your network.