I don’t know if you are going to make a realtime scanner or step by step, in my case (realitime) the fire of the light source must be with 0 delay (ok a few ns) so I had to make the control all in hardware, microcontroller has not fixed lag even if you do all the code in assembler, and the lag is then unsteadyness. On micro I did all the pid of the synched motor. I use a very pin focused so I can find the point where the film is unscratched from previuos claws of projectors. Through the film detecting