Micro Controlled Scratch Built Turntable

[Jim]

I am at the control stage of my scratch built turntable. My intent is to rotate the table with a bipolar NEMA 3 motor, via belt and pulley. I am using an Arduino micro control board in conjunction with a AF motor shield.
Once the sketch is written and loaded into the MC, the bridge rotates to predetermined locations via the step indexes of the motor. Returns the bridge back to home. Rotate left or right. Control speed for a soft start and stop of the bridge is written into the sketch. The motor step indexes are accurate and returns the bridge to exact location with no mis-alignment of the the bridge to the tracks.
In present configuration(single button on MC) this only allows for operation of one sketch. I need to operate 10 sketches to allow access to all track legs around the turntable.
I am having issues on how to get enough of the necessary pins for the MC, motor shield and interconnecting a 4*4 matrix keypad and a LCD display.
To work properly each rail section requires its individual sketch with adjusted parameters and individual execute button.
T button to get to he matrix keypad would provide the grandkids a simple, push the button that corresponds to the track they want.

Simple solution is to spend 1,500 for a pre built. Whats the fun in that.

Any past experience would be greatly appreciated.
Thank you