Project "Perscope booth" is an international three month project which is being created within partnership between Leibniz universität Hannover and Peter the Great St.Petersburg polytechinc university. First stage of the project was created during the VIII Fab Lab Polytech school.
Step 1: Concept
The main idea was to connect two cities: Hannover and St.Petersburg with a constant connection through a periscope with a display which will allow you to take a peek at what's going on there. So, here are the objectives we'd have to archieve in order to make the project:
- Syncronize two Raspberry pi's through Internet
- Make booth itself
- Make “periscope” with LCD display and censor which defines angle of view
- Make a rotating platform for web camera
- Transmit control signal form periscope censor to motor of rotating platform which is connected to another Raspberry pi and transmit video stream to display of another Raspberry pi
- Make a censor which can say if somebody’s using a booth to let people from another city know that they’re being watched so they could greet that person
- Make another set of devices to deliver it to Hannover
Step 2: Booth
As we were short on budget we had to make it as cheap as possible. So we decided to make it as a floor, celling four collumns and two lightboxes for the sides with some info about cities we are connecting.
We milled roof and floor on a milling machine of 18mm plywood and got 40x40 wooden timber for collumns which we attached to the milled parts with metal collumns and screws. Also, to make it more transportable, we attached four wheels to the floor.
Step 3: Rotating Platform With Censor
As were unable to get fancy motors with encoders we had to reinvent a bicycle so we made our own angle censor with a resisor. It's extremely cheap and allows us to read the angle from 0 to 360 degrees but we lost the ability to rotate a periscope at more than 180 degrees each way. We made a modular platform with motor, resistor and 1:1 gear. All the parts were made on a laser cutter. Censor for periscope is quite similar.
Step 4: Periscope Helmet
As 3D printing a helmet would be extremely long we decided to make it on a milling machine using 2.5D milling and then conntect layers with screws and PVA glue for wood.
Step 5: Getting Video Stream
This was the first and only challenge we took with using Raspberry Pi. The main idea is to transfer video stream from the camera to Web and then connect to an ip adress from another device. We used motion service of Raspberry and then after dozen of reinstalling system (the Internet connection crashed constantly so we couldn't install the system without errors for a long time) we finally got a picture and could connect to a camera in local web with a smartphone.
Step 6: Materials and Components
For one set of devices during Fab Lab Polytech school we used
- 2.5 sheets of 18mm plywood
- 1 sheet of 4mm plywood
- 2m LED stripe
- 12 V power supply
- 5V power supply
- Raspberry Pi model B
- Nema 17 stepper motor
- Stepper motor driver L297
- 50x80x16 bearing (№6010)
- Web camera
Step 7: Successes and Failures
What have we managed to do:
Basically, the mechanical part
- Rotating platform
- Getting video from camera
- Connecting from separate device to camera video stream
What yet has to be done:
- Another portable set of devices to send it to Germany
- Making the censor work and making the program to control the motor with data from periscope censor
- Syncronizing two Raspberries
So, in conclusion, we have to make almost the whole programming part and we have three months to master our Raspberry Ri skills.
Step 8: Credits
Xuebing Zhang, - programming engineer
Leonard Shmidt, - mechanical engineer (Booth)
Anja Linke, - designer (LightBoxes)
Ekaterina Svetlichnaya, - mechanical engineer, fitter
Ilya Antonov, - programming engineer, mechanical engineer (LightBoxes), fitter
Gleb Miroshnik, - mechanical engineer (Periscope), technician, fitter