Otto's nodes and launch files that do not belong elsewhere and don't deserve their own package.
The node otto_pid_tuning.py is used to tune PID parametes.
It subscribes to cmd_vel and otto_ticks and publishes a otto_pid_tuning_val message.
You can use rqt_plot to plot the values and tune your PID.
The node otto_odom_laser_calib.py is used to calibrate the odometry parameters and the laser pose.
It subscribes to otto_ticks and publishes the left and right wheel velocities (in radians/s) on /otto_odom_calib topic.
The data published on /otto_odom_calib, together with the data on /scan topic can be used with the package OdomLaserCalibraTool to automagically get the wheels radius, the distance between the wheels and the laser pose.
The node joy_to_cmd_vel.py subscribes to joy and publishes a cmd_vel msg.