Secret door is a project that opens a hidden department in a bookshelf. a 12v motor powers the self to come out when requested.
Step 1: Components/materials
a list of the materials/components you should own before starting:
- wooden plates/ closet(old)
- screws, nuts and bolts
- 12v motor + adapter
- sound sensor
- relais which will take 3.3v
- raspberry pi
- Photo-transistor and infrared led
- resistors : 220
- resistors : biggest you find (combined 1000+ Kohm)
Step 2: Put the Closet Together
putting the closet together
by sawing the wood. measure your books, based in this measurement you will decide the with of the shelf. i took 5 books of 5.5x 27 cm. so a width of 30cm, and a height of 58cm. then another plank for the bottom and the top and the middle.
once hooked up you can cut a hole on one side of the closet so a compartment can come out, also make a box that matches this compartment
The motor gives us a rotation motion which we must transform into a horizontal movement. We will use the system displayed in the picture. Saw a circle out of wood and apply an other longer piece to it with nuts and bolts, make sure he long piece can still easily turn on its own.
now attach your motor to the circle so it is able to turn without any friction. I used a a long bolt for this which is attached to the motor and turns the circle.
attach the long piece with the box so the motor pushes out the box when turned on. Attach the motor along with his adapter and relais to you can now turn it on and off.
Step 3: Setting Up Components
Hook up the component on the desired locations.
i chose the back for the rfid, the top front for the sound sensor (should be at front for maximal pickup). And the top middle for the photo-transistor.
hook them up to the right pins on your raspberry pi. check out the scheme for more info. only thing that is incorrect is the motor. i worked with a stepper motor at first. but it wasn't powerful enough so i switched to a 12v AC motor.
the photo-transistor needs to have great Resistance for it to give a high signal on incoming light.
a link to hook up the rfid: click here
Step 4: Scheme
A closer look on how the circuit should look like.
Step 5: Code
a link to my github where you can find all the code: