linuxjoystick

Linux joystick. More...

Linux joystick.

The linuxjoystick driver reads data from a standard Linux joystick and provides the data via the joystick interface. This driver can also control a position2d device by converting joystick positions to velocity commands.

Compile-time dependencies

• <linux/joystick.h>

Provides

• joystick : joystick data
• position2d : joystick data represented as 2-D position data. Raw X-axis, Y-axis and Yaw-axis values are reported as pos[0], pos[1] and pos[3] in the position packet (all other fields are zero).

Requires

• position2d : if present, joystick positions will be interpreted as velocities and sent as commands to this position2d device. See also max_speed, and deadman_button options below.
• gripper : if present, joystick buttons will be used to control given gripper (open, close, store, retrieve, stop).

Configuration requests

• None

Configuration file options

• port (string)
  • Default: "/dev/js0"
  • The joystick to be used.
• axes (integer tuple)
  • Default: [1 2 0]
  • Which joystick axes to call the "X" , "Y" and "Yaw" axes, respectively.
• axes_maxima (integer tuple)
  • Default: [32767 32767 32767]
  • Maximum absolute values attainable on the X, Y and Yaw axes, respectively.
• axes_minima (integer tuple)
  • Default: [0 0 0]
  • Minimum values on the X and Yaw axes, respectively. Anything smaller in absolute value than this limit will be reported as zero. Useful for implementing a dead zone on a touchy joystick.
• deadman_button (integer)
  • Default: -1
  • When controlling a position2d device, if deadman_button is >= 0, this joystick button must be depressed for commands to be sent to that device.
• max_speed (float tupple, m / sec or angle / sec)
  • Default: [0.5 0.5 30]
  • The maximum absolute X and Y translational and rotational velocities to be used when commanding a position device. (Y is only revelant for holonomous robot)
• scale_pos (float tuple)
  • Default: [1.0 1.0 1.0]
  • Position2d readings scale
• timeout (float)
  • Default: 5.0
  • Time (in seconds) since receiving a new joystick event after which the underlying position device will be stopped, for safety. Set to 0.0 for no timeout.
• Notes:
  • Joysticks use X for side-to-side and Y for forward-back, also their axes are backwards with respect to intuitive driving controls.
  • This driver does not swap any axis, you have to handle this in the configuration file options via "axes". However the defaults values should suit your needs.
  • This driver reverse the axes so that the joystick respect the intuitive driving controls.
  • The Y axis is only revelant for holonomous platform (like the WizBot).

    Examples

    Basic configuration

driver
(
  name "linuxjoystick"
  provides ["joystick:0"]
  port "/dev/js0"
)

Provide a position2d interface, instead of a joystick interface.

driver
(
  name "linuxjoystick"
  provides ["position2d:0"]
  port "/dev/js0"
  scale_pos [ 0.0001 0.0001 0.0001 ]
)

Controlling a Pioneer, plus remapping joystick axes and setting various limits.

driver
(
  name "p2os"
  provides ["odometry::position:0"]
  port "/dev/usb/tts/0"
)

# 1 m/sec max linear velocity
# 30 deg/sec max angular velocity
# Axis 4 is X
# Axis 3 is Yaw
# Y is not used here
driver
(
  name "linuxjoystick"
  provides ["joystick:0"]
  requires ["odometry::position:0"]
  max_speed [1 0 30]
  axes [4 -1 3]
  axes_minima [5000 0 5000]
  port "/dev/js0"
  alwayson 1
)

Controlling a WizBot in Gazebo, plus remapping joystick axes.

driver
(
  name "gazebo"
  provides ["simulation:0"]
  plugin "libgazeboplugin"
  server_id "default"
)

driver
(
  name "gazebo"
  provides ["position2d:0"]
  gz_id "position_iface_0"
)

# 0.5 m/sec max linear velocity
# 120 deg/sec max angular velocity
# Axis 1 is X
# Axis 2 is Y
# Axis 0 is Yaw
driver
(
  name "linuxjoystick"
  provides ["joystick:0"]
  requires ["position2d:0"]
  max_speed [0.5 0.5 120]
  axes [1 2 0]
  port "/dev/js0"
  alwayson 1
)

Todo:

Add support for continuously sending commands, which might be needed for position devices that use watchdog timers.

Author

Andrew Howard, Brian Gerkey, Paul Osmialowski