I'm working on an airsoft turret that can move on the X axis. I'm wanting to use some kind of sensor for finding its target. One idea I had was using an IR emitter and when something breaks the beam it would fire, but for that would I need an IR emitter and a receiver or is there any way I could use just the emitter. If I use IR I would end having more then one emitter so it could have 180 degree radius of sensor. My other idea is just to control it threw a laptop and webcam. I would prefer to have it so I do not have to sit and use it and have it go by its self. Is there any other sensors I could use? Any ideas or suggestions would be very helpful thank you.