Homemade Dome observatory Rotation sensor module

This short video shows my homemade module designed to detect rotation angle and direction of my motorised dome observatory. The module converts rotational movement from a sprocket wheel driven by a perforated metal belt fixed on the inside of the rotating circular beam on which the Dome rests into pulses generated from an inline modified rotary encoder.
Direction of movement is easily derived by sensing the voltage polarity going to the motor terminals.
More details about this and the whole Homemade dome project on my blog at
ravenandowl789...
Music " Windmills of your mind " by Ed Ames.