Softgun turret, IR led array for positioning?

We are some guys building a softgun turret and using several arduinos talking togheter nano's and a mega.

we have made a movementdetection array around the turret and need to have some positioning,

we have mounted one ir-led in each pir sensor sone meaning to send a continous code for recognizing friendly movement. the trouble is how do we send individual signals on 4 ir led's on one Mega?? currently struggling to find a viable example that works...

second on the same Mega we have added 4 ir-sensors for recieving an ir signal from the spinning top (we will be able to move 360degrees.) i tried adding 2 sensors and it seems that because of the lib i cant get an individual reading.. how do i make this work? is there a lib out there somewhere??

we are using motor controllers and have geared motors so we need these sensors to keep track of relative position, building in switches is not longer an option.