The door is driven by a continuous rotation servo motor with a pulley system. There are two hidden push buttons that control the servo motor rotation. Inside the enclosure there is a Normally Open mini contact switch (NO), and 5 LEDS . As the door slides open the switch goes from normally open to close state, turning the LEDS ON. When sliding door closes, it turns the LEDS OFF, by changing the contact switch back to N.O state.
The circuit is a typical and simple servo motor driver/tester, using the 555 IC timer. This circuit works great with continuous rotation servos. I built this project using whatever parts were handy and available that I could use at the time it was built.
There are a lot of features you can apply to this project, for example using a microcontroller like the Arduino to control a motion sensor, Clapping sensor, Wireless Remote, a camera that text you pictures when the door is been open, use an entry key pad code to activate the door. There are a lot of things you can add to this project, to make it more of a spy kind of gadget.