The video shows a detailed implementation of sinusoidal acceleration and decelaration for achieving smooth motion of the RR1 robotic arm revision 2. Mathematics behind is discussed and important calculations are explained. Specifically I show what calculations are needed so that a robot joint travels exactly a specified angle (which is a specified number of steps) by sinusoidal acceleration/decelaration speed profile. Sinusoidal speed profile reduces vibrations of the robot as it has zero derivative (acceleration) at the moment when the joint starts/stops.