This is my first post Related to Projects and today i will describe ‘Propeller Display’ project. Me and my friend Rushi, we both made ‘Propeller Display’ project during our under-graduation. Below is the photo of the project.
Project uses Microchip PIC16F84A Microcontroller. Below is the brief specification for same.
- 18-Pin, 8-bit microcontroller
- Operating Speed – 20MHz max.
- 1024 words of program memory (word length – 14 bits)
- 68 bytes of Data RAM
- 68 bytes of Data EEPROM
- 14-bit wide instruction words
- 8-bit wide data bytes
- 15 special purpose registers
- Four interrupt sources: Ext. RB0/INT pin, TMR0 overflow, PORTB<7:4> interrupt-on-change, Data EEPROM write complete
The principle of this project is perception of Vision(POV). Quating from Wikipedia,
“Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina.”
From the definition we can understand that our retina retains the view of past image for approximately 1/125 sec = 0.008 sec. Lets, consider a example of torch, if one project the light-spot on wall, further he moves the light-spot circle back and forth horizontally and gradually increases the speed. Then at a time, eye of viewer can not differentiate the light-spot circle and it is viewed as one straight horizontal line of light instead of circle.Same idea applies here. In propeller display, continuous projection of LED’s patterns (Some LEDs are ON and others are OFF) at specific location with rotating entity, gives visual appearance as steady patterns.
Below is the Schematic of project. We have used Jon stanley’s propeller clock as Reference design.
|10K ohm resister||5|
|120 ohm resister||7|
|4 MHz crystal oscillator||1|
|220 µF capacitor||1|
|3 mm yellow LED||7|
|On/Off Control switch||1|
- 9V battery to power circuit on breadboard (which will be converted into 5V)
- 12V volt variable power supply for DC motor
- ICSP programmer
For more detail: How to make a ‘Propeller Display’ using PIC microcontroller