Project ReportPropeller Clock Submitted By:Shubham Kumar Himanshu Chaudhary Chandan Sah Deepika Grover Submitted To:Mr. Pradeep Mittal Section-E3106 we can display a clock. . This “illusion” is based on inertia of human eye. the connected seven LEDs are scanned line by line at a very fast speed which makes the observer to observe those led display clock. “What we see is a blend of what we are viewing and what we viewed a fraction of a second before”. It will be the coordination of electrical. The motor spinning fast enough that the human eye will perceive all of the display is on at once. The motor spins at a constant rate such that the LEDs rotate around a centre pivot point. The mechanical scanning mechanism. consisting of the IR interrupt sensor MOC781. Microcontroller AT89C2051:.Interrupter module is our hardware sensor module. It has to be programmed so that it will both keep time and also send the appropriate signals to the LEDs to light them in the correct sequence. As the LEDs spin around they light up sequentially such that they will display the current time. Now by synchronising these light emitting diodes. which is a derivative of 8051 family. The persistence of vision. Components Used:Interrupter Module (Opto Coupler) :. electronics and some mechanical engineering. which is performed in the clock when the motor is turned on.This project is based on the microcontroller AT89C2051. Its looks like the digital numbers are floating in the air.Abstract:This project is a different view of holographical clock construct in linear array arrangement. Introduction:The propeller clock is a linear array of light emitting diodes. rotating at a high angular velocity to generate a circular screen. and the viewer will be able to read the time constantly. and keeping in mind the concepts of persistence of vision & limit of resolution. A microcontroller is used to keep the time and blink the LEDs in an appropriate pattern to show the numbers. LED module consisting of 7 bright LED is fixed in another side of the arm of our project. This task is achieved using circular rotation of the whole circuit assembly.LED Module:. DC Power Supply:. we used a DC motor with 1200 rpm speed as the prime mover. while +9V to the motor. We have to provide +6V to the microcontroller. So. a regulated DC power supply is required. DC Motor:.For microcontroller. as well as the DC motor.Repeated scanning of the display is must for continuous vision. Circuit Diagram & Block Diagram:- . so that the interrupts INT0 and T0 are enabled. (IT0=1) 5. 5. Load proper value in IE register. Subtract the answer from 256. Return from interrupt. start the timer. Start the timers. Timer 0 Interrupt :1. Move th1 and tl1 into convenient registers. reset the video RAM pointer and character segment pointers to their initial respective 6. Call the display routine. Main routine 1. Move input string to the video RAM area. (P3 = 0FFH) 6. (IE =83H) 2.Algorithm:i. Now. Return from interrupt b. and timer0 as 8-bit auto reload mode timer. 4. Interrupt Routines :a.(call„ramc‟ function) 7. ii. and load the Result in th0. Clear timer overflows flag. 2. Configure port 3 as input port. Offer higher priority to the INT0 (External) interrupt. ( TMOD= 12H) 4. 3. Initiate an infinite loop. 7. 2. Configure timer 1 as 16-bit timer. Stop the timers.(IP = 01H) 3. Divide this 16 bit value by our total number Of segments. 8. . INT0 should be configured as edge interrupt. 3. External Interrupt 1.