Beginning of forcefeedback node, it looks like https://www.kernel.org/doc/Documentation/input/ff.txt supports more types than fftest.c shows.  Need ros params for the effect index, effect max num, effect type, effect waveform,  period, magnitude, offset, phase, direction, attack length, attack level, fade length, fade level, trigger button, trigger intervale, replay length, replay delay for the periodic type, and weak and strong magnitude for the rumble type.