Testing the hardware interface¶

This tutorial assumes that you have already been able to compile and install the package. If not, please refer to the related instructions in the building/installation instructions.

For this example, we are using 2 dynamixel actuators : MX28 . It will by default launch two feed-forward only controllers (one position and one velocity) and a virtual controller that publishes the states of the two actuators.

Connect motor

with your USB2DYNAMIXEL device or your favorite dynamixel interface.
Supply power

USB2Dynamixel does not supply power to Dynamixel. Therefore, the power must be supplied separately to operate Dynamixel. We are recommanded to use : one laboratory power supply or SMPS2Dynamixel .

Go inside your libdynamixel directory

Check serial interface

open a terminal and simply type : ls /dev.

check your serial interface’s name, in our case ttyUSB0.
Check device’s ID

open a terminal and simply go into your libdynamixel directory : cd /home/USER/Resibots/libdynamixel. Now, you can check with our tools interface if your motors and the libdynamixel work correctly :

./build/src/tools/dynamixel -p /dev/ttyUSB0 -b 3000000 list

-p device interface

-b dynamixel’s baudrate (known)

list command to list all connected dynamixel

Go inside your dynamixel_control_hw directory

URDF File
check the URDF file : urdf/sample.urdf
joints names

joints limits

Configuration file
check the example configuration file: config/sample.yaml
id parameters

serial_interface

baudrate
Launch file
Check the launch/sample.launch file.

It will by default launch two feed-forward only controllers (one position and one velocity) and a virtual controller that publishes the states of the two actuators.

Once you are sure that it’s correct, you can:
roslaunch dynamixel_control_hw sample.launch
Check topics and params:
```
rostopic list
rosparam list
```

or visualize it on rviz

Note

if the arm doesn’t appear on rviz, try to change Fixed Frame in global option display.