Joy2Twist

Dockerized ROS node allowing control of ROS-powered mobile robots with Logitech F710 gamepad. Joy2Twist node is converting sensor_msgs/Joy message to geometry_msgs/Twist in order to provide velocity commands for the mobile robot. Therefore this package is compliant (but not supported by Husarion) with any other gamepad controller which is able to publish the sensor_msgs/Joy message.

Setup joy

Connect joy via nano USB receiver and make sure it is in DirectInput Mode (switch in front o the pad with letters D and X, select D).

To test if joy works, use jstest /dev/input/js0. If the output is:

jstest: No such file or directory

See ls /dev/input | grep js and find your joy number. If it differs, apply changes in compose.yaml and launch file.

Button mapping

Button	Function
LB	enable driving
RB	slow driving mode
RT	fast driving mode

If neither RB nor RT is pressed, the robot operates in regular driving mode.

To drive robot use sticks. By default, linear X and Y are held by the left stick. Angular Z is controlled with the right stick.

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ROS node API

ROS node is translating /joy topic to /cmd_vel topic.

Publish

• /cmd_vel (geometry_msgs/Twist)

Subscribe

• /joy (sensor_msgs/Joy)

Parameters

Following parameters change joystick axes mapped to given robot axes of freedom. For more information about parameter values, refer to the joy package wiki page.

• ~axis_linear_x (int, default: 3)
• ~axis_linear_y (int, default: 2)
• ~axis_angular_z (int, default: 0)

The robot can be operated at 3 scales of speed depending on pressed buttons. It's possible to adjust velocity scaling factors using a config file. The Units are m/s for linear movement and rad/s for angular movement.

• fast (float, default: 1)
• regular (float, default: 0.5)
• slow (float, default: 0.2)

Docker image

ROS2 distro	Supported architectures
galactic	linux/amd64, linux/arm64
humble	linux/amd64, linux/arm64

Available on Docker Hub

Demo

Controlling ROSbot 2 with a Logitech F710 gamepad

1. Clone this repo on your ROSbot:

   git clone https://github.com/husarion/joy2twist.git
   cd joy2twist/

2. Create demo/.env based on demo/.env.template file and modify it if needed (see comments)

   #SBC <> STM32 serial connection. Set:
   #SERIAL_PORT=/dev/ttyS1 # ROSbot 2
   #SERIAL_PORT=/dev/ttyS4 # ROSbot 2 PRO
   SERIAL_PORT=/dev/ttyAMA0 # ROSbot 2R

3. Launch on ROSbot

   Go to the joy2twist/demo folder and run:

   cd joy2twist/demo
   docker compose -f compose.rosbot.yaml up