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Configuring and Using a Linux-Supported Joystick with ROS
Description: This tutorial is an introduction to using the joystick connected to a desktop computer. After reading it, you should be able to bring up the joy node and display the data coming from the joystick over ROS.Keywords: joystick, driver
Tutorial Level: BEGINNER
Next Tutorial: Writing a Teleoperation Node for a Linux-Supported Joystick
Installing
Start by installing the package:
$ sudo apt-get install ros-indigo-joy
Configuring the Joystick
Connect your joystick to your computer. Now let's see if Linux recognized your joystick.
$ ls /dev/input/
You will see a listing of all of your input devices similar to below:
by-id event0 event2 event4 event6 event8 mouse0 mouse2 uinput by-path event1 event3 event5 event7 js0 mice mouse1
As you can see above, the joystick devices are referred to by jsX ; in this case, our joystick is js0. Let's make sure that the joystick is working.
$ sudo jstest /dev/input/jsX
You will see the output of the joystick on the screen. Move the joystick around to see the data change.
Driver version is 2.1.0. Joystick (Logitech Logitech Cordless RumblePad 2) has 6 axes (X, Y, Z, Rz, Hat0X, Hat0Y) and 12 buttons (BtnX, BtnY, BtnZ, BtnTL, BtnTR, BtnTL2, BtnTR2, BtnSelect, BtnStart, BtnMode, BtnThumbL, BtnThumbR). Testing ... (interrupt to exit) Axes: 0: 0 1: 0 2: 0 3: 0 4: 0 5: 0 Buttons: 0:off 1:off 2:off 3:off 4:off 5:off 6:off 7:off 8:off 9:off 10:off 11:off
Now let's make the joystick accessible for the ROS joy node. Start by listing the permissions of the joystick:
$ ls -l /dev/input/jsX
You will see something similar to:
crw-rw-XX- 1 root dialout 188, 0 2009-08-14 12:04 /dev/input/jsX
If XX is rw: the js device is configured properly.
If XX is --: the js device is not configured properly and you need to:
$ sudo chmod a+rw /dev/input/jsX
Starting the Joy Node
To get the joystick data published over ROS we need to start the joy node. First let's tell the joy node which joystick device to use- the default is js0.
$ roscore $ rosparam set joy_node/dev "/dev/input/jsX"
Now we can start the joy node.
$ rosrun joy joy_node
You will see something similar to:
[ INFO] 1253226189.805503000: Started node [/joy], pid [4672], bound on [aqy], xmlrpc port [33367], tcpros port [58776], logging to [/u/mwise/ros/ros/log/joy_4672.log], using [real] time [ INFO] 1253226189.812270000: Joystick device: /dev/input/js0 [ INFO] 1253226189.812370000: Joystick deadzone: 2000
Now in a new terminal you can rostopic echo the joy topic to see the data from the joystick:
$ rostopic echo joy
As you move the joystick around, you will see something similar to :
--- axes: (0.0, 0.0, 0.0, 0.0) buttons: (0, 0, 0, 0, 0) --- axes: (0.0, 0.0, 0.0, 0.12372203916311264) buttons: (0, 0, 0, 0, 0) --- axes: (0.0, 0.0, -0.18555253744125366, 0.12372203916311264) buttons: (0, 0, 0, 0, 0) --- axes: (0.0, 0.0, -0.18555253744125366, 0.34022033214569092) buttons: (0, 0, 0, 0, 0) --- axes: (0.0, 0.0, -0.36082032322883606, 0.34022033214569092) buttons: (0, 0, 0, 0, 0)
On electric and above the new sensor_msgs/Joy message is emitted, which includes a Header:
--- header: seq: 9414 stamp: secs: 1325530130 nsecs: 146351623 frame_id: '' axes: [-0.0038758506998419762, -0.0038453321903944016, -0.0, -0.999969482421875, 0.0, 0.0] buttons: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] --- header: seq: 9415 stamp: secs: 1325530130 nsecs: 146351623 frame_id: '' axes: [-0.0038758506998419762, -0.0038453321903944016, -0.0, -0.999969482421875, 0.0, 0.0] buttons: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] --- header: seq: 9416 stamp: secs: 1325530130 nsecs: 146351623 frame_id: '' axes: [-0.0038758506998419762, -0.0038453321903944016, -0.0, -0.999969482421875, 0.0, 0.0] buttons: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] ---
