The Original design idea came from this video https://www.youtube.com/watch?v=Su6O6155UJM. The designer published the 3D CAD files but they were not compatible with my CAD software so I recreated the mechanical design with FreeCAD and adapted it to my TEAC stepper motors.
The motors are driven by a pair of A4988 stepper motor drivers that are controlled by an NEC V25 SBC I had from an older project. The controller board runs a drive+controller application that can be accessed through a serial link and managed through either a serial console (e.g. minicom) or commands issues by a remote program (I use a set of Python scripts for different applications).
This setup allows the controller to maintain a simple set of command primitives that are use by higher level code to implement more complex applications such as integration with OpenCV for object tracking.
Mechanical design: (https://grabcad.com/library/differential-pan-tilt-1)
Software: (https://github.com/eyalabraham/differential-pan-tilt)
Watch this page for more info in coming weeks.