6.3.7 C code framework

You can code the velocity profile logic anyway you want. However, from the organization point of view, I suggest you use a structure to include all the properties:

$\begin{lstlisting}{} struct MotionProfile { struct FreqDiv vel; // velocity con... ...n; // sign of velocity int a_sign; // sign of acceleration }; \end{lstlisting}$

Given that pmp is of type struct MotionProfile *, you should initialize it as follows:

$\begin{lstlisting}{} pmp->vel.freq = 0; // initially stationary pmp->vel.sum = 0... ...initially nowhere to go pmp->vset = 0; // initially stationary \end{lstlisting}$

In this example, the function step_func must handle positive and negative velocities. While pmp->vel.freq represents the magnitude of velocity, pmp->v_sign represents the direction. Similarly, the function accel_func must take into account the sign of acceleration, stored in pmp->a_sign.

step_func has to handle the sign crossover of pmp->D. This is easy because pmp->D is a signed number. accel_func has to handle the sign crossover of velocity magnitude pmp->vel.freq and velocity direction pmp->v_sign.