POV GLOBE

The New and Cool Way of advertising

Abstract

The idea of this project is to make a cool and unique 3D Spherical Display.The team of 5 freshers did their best to make the spherical display, displaying the phenomenon of Persistence of Vision using a ring rotating at a very high rpm with a LED strip on its circumference which was adjusted to glow so as to make the model capable of displaying floating text, user enter words and blurred images.

Motivation

The main driving force about this project was that it was different than the core models with moving servo motors, controlled by programs, it was cool, has a colorful look and is a bit unique.

Mechanical Sructure

It consists of a ring (which we made out of a badminton racket) mounted on a heavy cardboard(to decrease the vibrations of rotating ring), it also consisted of a slip ring(self made using an stainless steel cylinder, copper wires and rubber bands!!).

Electronic Component Used

1. Arduino UNO
2. Cytron Motor Driver
3. Hall Sensor
4. High Torque Bane-Bot 18W DC Motor
5. Adressable -RGB LED strip(60LEDs/m)(20 LEDs on the semicirle

Working

Principle The Persistence Of Vision phenomenon

• The ring with LEDs mounted on it was rotated at around 1500 rpm so as to give effect of 25fps display.
• The feedback for the completion of a revolution was taken using hall sensor mounted on the side.
• According to the feedback from hall sensor, angular velocity and time period of every revolution was calculated.
• Dividing the revolution time into various segments, the LEDs were lighted according to the printed text.
• The whole system was powered by 12V LiPo battery and power was transmitted to LEDs using slip ring.

Cost Structure

Item	Cost(₹)
LED strip	2k
Bane Bot 18V DC motor	15k
The arduino UNO	400
Cytron Motor Driver	1k
The hall Sensor,wires,voltage regulator etc.(other electronics)	800
Total	19.2 k
Overall it was descent for its cost.

Limitations

• At present we are able to diaplay 4-5 alphabets since the adrduino UNO clock has least delay of 1ms, the individual vertical strips expanded due to a large time difference between them, which made the letters wide.
• At present ,if we try to show some images ,they appear distorted due to the above limitation and the unavailability of higher density LED strip.
• The present slip ring isn't that efficient in, it when operated at angular velocity higher than 1500 rpm,it starts to show noise in the data cable, making the display bad.

Future Improvements

• To increase the number of alphabets covered.
• To display images and if more advanced ,videos.

Team Members

1. Chanda Kumari
2. Kshitij Bithel
3. Lipi Shreya
4. Sanyam Jain
5. Vivek Kumar

Mentors

1. Aditya Raj
2. Prashant Kumar
3. Tarun Saxena
4. Tejaswa Soni
5. Vedvyas Dhanturi

References

* Build Your POV Globe -Makezine

• How To Control WS2812B Individually Addressable LEDs using Arduino
• Interfacing Hall Effect Sensor with Arduino

For Videos and More Images Click here