sbus_serial

ROS 2 package for parsing Futaba SBUS serial data from a RC receiver for remote control (teleoperation) of ROS-based robots.

SBUS is a serial protocol for RC receivers where the values of up to 16 channels are sent over one serial channel.

Read the Wiki which contains all the information you need to use this package.

The package contains the following executables:

• sbus_serial_node containing:
  • sbus_serial: node reading SBUS data from a serial port and publishing Sbus data
• sbus_cmd_vel_node containing:
  • sbus_cmd_vel: node subscribing to the /sbus topic and publishing corresponding Twist or TwistStamped message on the /output/sbus/cmd_vel topic. Use parameters and topic remapping as required. (See comments in sbus_cmd_vel_node.cpp for more info)
• sbus_calibrate (installed in the packages's share directory): stand-alone executable to calibrate data from the receiver (see details in the Wiki).

The package also contains the following custom interfaces:

• sbus_serial/msg/Sbus:
  Values received and mapped from the SBUS input.

ROS version

The code in this branch is written for ROS 2 Humble Hawksbill.

The ros1 branch contains the old code for ROS 1.

Compiling

Compile as usual: colcon build.

If you get an error saying, "boost/algorithm/clamp.hpp: No such file or directory", you need to install the Boost C++ libraries. On Ubuntu, run sudo apt-get install libboost-dev.

Usage

A typical setup will launch sbus_serial and sbus_cmd_vel nodes.

The sbus_serial node should be configured with port name (e.g. /dev/ttyS0) and appropriate values for min/max (see the Wiki).

The sbus_cmd_vel node should be configured with Sbus min/max matching the output from the sbus_serial node and appropriate min/max values for Twist speed and turn. The published topic (/output/sbus/cmd_vel) should also be remapped to the appropriate topic.

Turtlesim

The package contains a launch file to use the Sbus to control the Turtlesim for testing.

The launch file launches turtlesim turtlesim_node and sbus_serial sbus_cmd_vel_node but not the sbus_serial_node as that could be running on another device (e.g. the SBUS RC is connected to a Raspberry Pi controller and the Turtlesim is running on a full desktop Ubuntu computer). So be sure to launch sbus_serial sbus_serial_node with appropriate parameters separately or the test will be real boring.

The sbus_serial_node should output Sbus values from 0-255 and channel 3 (throttle) is used for forward speed while channel 1 (aileron) is used for turning.

If the minSpeed parameter is set to a negative value, the turtle will reverse when control stick is at bottom.