The original design came from this video. 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 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.

Web page: (https://sites.google.com/site/eyalabraham/differential-pan-tilt)
Mechanical design: (https://grabcad.com/library/differential-pan-tilt-1)
Software: (https://github.com/eyalabraham/differential-pan-tilt)
YouTube: (https://youtu.be/LF1JT0Pmddc)

• Controller and driver software
• Python applications and modules