Also, the DC motor's and the cooling fan's output pins are marked on this image.
The cooling fan output is used to power the Arduino: it outputs 7-12V depending on the cooling needed. Although Arduino Pro Micro has a RAW input which should handle this range, it turned out that it is too much for it. So we connected the cooling fan's output to Arduino's RAW input through a voltage regulator, which outputs 5.25V.
The DC motor output is used to detect when the projector tries to open or close the mirror: it outputs 12V and changes the sides of the + and - depending on the direction. We connected the two diode-protected stepdown converters' input to the red and black cables of the DC motor output, and the converters' output to the input pins of the Arduino.