JeffSinger wrote:You can't really trust the software to keep accurate track/time of stepper movement. CPU load is usually maxed out in image/video processing. When that happens some timers (threads) stop all together. I know what advantages steppers could have. The problem is that there isn't a stepper out there that you can just give a position command to like an RC servo. You'd have to build some sort of RC servo-stepper mutation where you somehow took the PPM board and POT from a servo and mounted it to a stepper. You'd have to create a controller that was a mix of stepper and servo so that you fed it position commands instead of steps and instead of sending out DC current to a regular DC motor, it controlled the movement of a stepper. As far as I know, nothing like that exists.
Like I said before, stupid in is stupid out regardless of the hardware.
Any real image processing app is going to use dedicated hardware for the job. It would at least be done on a GPU. That leaves basically the entire CPU available for the motor control.
Besides, motor control on a modern CPU is only going to need something in the vicinity of 1% of the CPUs time to deal with the motor. If your app is that CPU bound that you can't spare the 1% for decent motor control then stepper vs. servo is the least of your problems.
Heck, in many robotic apps the motors are only updated once every millisecond or so, which is still at least an order of magnitude faster than they really need to be. Even running a pid the math to deal with the motor can be done in less than a microsecond.