When looking for a turntable solution for my layout I found a few commercial sites, such as this one. However the customer comments I read were not satisfying, and the response from the provider even less so. One of the most common comments was that the indexing system does not work well; creep in the course of usage resulted in tracks not being alligned properly anymore after hours of operation. The comments from the provider were not reassuring: he blamed that the creep was the result of the wooden support frames crimp and expansion due to moisture or whatever. So one of the foremost goals in this project is to have flawless indexing, and total-zero creep over the course of usage. For that matter I developed an algorithm that, during calibration, measures the exact amount of stepper moter steps to perform an exact 360° 0' 0" 0.1" etc.. turn. Several other requirements were set as goals prior to starting the actual development. One of the peculiar and most important hardware parts (besides the stepper motor) is the indexing sensor. Some other projects use a Hall effect sensor: this sensor uses the magnetic field of an external object to sense its presence. There is however a very big disadvantage to this sensor. Since magnetic fields do not have clear on/off boundaries it is virtually impossible to get a magnetic object to approach within a specific distance where the sensor will detect its presence and expect that distance to be over and again to be identical within millimeters, or for the requirement of turntable operation, within tenths of millimeters. The decision to use in this project a specific optical detector, with a narrow and highly selective field of view, was taken after hours of testing of its repeatability and repetitivity (statistical terms describing the accuracy of measurements). This detector is described further along with all the other specifics of this project in this Github page.