MICROCONTROLLER-

BASED PROPELLER CLOCK

Abstract - A particular type of circular LED display is referred to as the propeller clock. It originates from the Persistence of Vision (POV) theory, which means that if something appears at a very high speed at the same location, at least 50-60 times per second, our brains prefer to assume that although it really is not, it is permanently there. This propeller clock has been scanned mechanically and displays digital format data. It was made from scrap and can be used everywhere and everywhere, and the most surprising thing is that the show is crystal clear. The maintenance and repair of such a display is so simple that it can be taken care of by someone with just a little knowledge of electronics. Via different applications, all the synchronisation can be enforced. It uses the Keil C51 Compiler to write 8051 microcontroller applications in C. The clock portion of the programme operates using interrupts and timers. We used the microcontroller AT89S52. The Atmel AT89S52 is a Full Static CMOS Controlle 8051 based.

Keywords: POV principle, Microcontroller AT89S52, IR LED, DC, Motor, Interrupter Module.

1 INTRODUCTION

Propeller is a concept commonly associated with any revolving circular object [1]. A prime mover must be connected to it, since this project requires a rotating circuit assembly. To display different characters and symbols on its assembly, this project uses bright Light Emitting Diodes ( LEDs). That's why the name of this project is 'PROPELLER LED CLOCK'.

This project began with the Persistence of Vision, a basic concept that is often experienced in our daily lives.

It is dependent on the human eye's vision capacity that an after-image is assumed to exist for approximately 1/25th of a second. So, if any images are detected by a human at a rate of 25 images per second, then they seem to be continuous. A TV is a typical example; every picture is re-scanned 25 times every second, making it continuous. In addition, if every glowing object at a rapid pace is rotated circularly, a continuous circle can be seen. 8 LEDs are rotated in a circle using this simple concept, thus displaying 8 concentric circles. But if these LEDs are modified somewhat at precise intervals, it is possible to design a steady display pattern.

Many current systems use the concept of POV, but each pixel is displayed by an

It uses a person LED. This, also for small-sized screens, leads to a large number of LEDs. But it is possible to minimise the LED count to a large degree by using a propeller style monitor. As few as 8

LEDs can perform more than one task

LEDs, 525. Cost-effective solutions for large public displays and information systems are included in its implementations. At train stations, bus stands and many such locations, it can directly replace various information displays.

II WORKING PRINCIPLEThe commonly used AT89S52Microcontroller is the most significant portion of the Propeller Clock. The IR LED, which is stationary, is attached to the revolving assembly frame. When the IR rays sent by the IR LED fall on the photodiode placed on the rotating PCB, a low pulse is produced on the microcontroller's interrupt pin, which leads to the desired pattern generation. Since we used internal programme execution, with the aid of Vcc[2],

The EA (external access) pin was elevated. For the reset of the reset, an effective reset circuit is given.

With a microcontroller. The positive LED terminal is interconnected and connected to the 5V supply. At PORT0, Logic 0 level will lead to LED illumination. We defined a standard notation to show the numbers, using the following 5 * 8 matrix notation:

Gaurav Bhardwaj, Nikhil Goel, Somya Agarwal, Yatin Goel and Khushbu Bansal* Department of ECE, ABES Engineering College, Ghaziabad, U.P

*Corresponding Author: khushbu.bansal@abes.ac.in

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when the IR LED light rays are obscured because of some fully opaque artefacts. The microcontroller or other discrete hardware will quickly detect this shift in logic.

(iii) Mechanical Assembly

In the proper execution of this undertaking, mechanical assembly played an important part. The monitor must be scanned on a circular path by spinning the whole assembly. [4]The underlying concept we have created is our own through numerous ways in which to do so. The diagram below showed the most accurate way to pick. One huge challenge in this case was how to produce +5V

Circuit of turning.

This was attempted by using two or three multiple strategies, but we eventually determined the route, as seen in the figure below.

The supply of GND through the engine shaft is seen in the diagram. By arranging friction discs brush arrangements, a Vcc terminal is associated. The brush holds always in touch with the disc, so that the current can always be supplied. The main goal was to achieve perfect equilibrium and strong mechanical strength overall. We also included a long screw for weight adjustment, and weight may be fixed or removed by adding / removing the metal bolts. When the mounting is well balanced, higher stability can be obtained and rotated even at high rpm. The average performance of the monitor was increased.

(iv) DC Power Supply

Constant output of a fixed voltage power supply

+5V contains a bridge rectifier, a condenser philtre and IC LM7805 3-terminal controller[5]. This energy source will source +5V and up to 500mA of load current. The 12V AC is derived from the transformer output. The input condenser (Regulator 's response to abrupt load changes) is used to boost the transient response of the regulator IC. The noise present in the performance is also useful. For proper operation of the regulator, the drop-off voltage (Vin-Vout) must be at least 2V for all operating conditions. With the relation of the performance of IC LM7805 we supplied the microcontroller and LED.

III METHODOLOGY

A. Hardware Description

A detailed overview of all the components shown in the above block diagram is given in this section. The related schematics and work are explained in every description.

(i) LED Module

On one side of our project's arm, the LED module consisting of 8 bright LEDs is mounted. These LEDs are linked to each microcontroller port pin with a 470 ohm current limiting resistor.

DC Motor

For continuous vision, repeated scanning of the monitor is a must. Using circular rotation of the entire assembly, this role was accomplished. A DC engine was, thus, used as the prime mover.

(ii) Microcontroller AT89S52

The microcontroller AT89S52 is a low-power and high-performance 8-bit CMOS microcontroller with 8 K bytes of programmable in-system Flash memory[3]. This product was manufactured using the high-density non-volatile memory technology of Atmel and is compatible with the set and pin out instructions of the industry standard 80C51. The on-chip Flash helps the machine or a traditional non-volatile memory programmer to reprogram its programme memory. The Atmel AT89S52 is a powerful microcontroller which provides a highly flexible and cost-effective solution for many embedded control applications by combining a versatile 8-bit CPU with in-system programmable Flash on a monolithic chip. The AT89S52 provides: 8 K bytes of Flash, 256 byte of RAM, 32 I / O blocks, Watchdog timer, two data pointers, three 16-bit timer / counter, six-vector interference architecture, full duplex serial port, on-chip oversetter, clock circuitry. The AT89S52 offers the following basic features. Furthermore, the AT89S52 is designed for service down to zero frequency with static logic and supports two power saving modes selectable by software. The Idle Mode stops the CPU while enabling the continued running of the RAM, timer / counters, serial port and interrupt device. The Power-down mode stores the contents of the RAM but freezes the oscillator, removing all other chip functions before the next hardware interrupter is reset.

Interrupter Module

The sensor module is made up of IR

MOC7811 Motorola Inc. interrupt sensor. A number of other choices have chosen this sensor because it has limited sizes, reliable interruption sensing and test case. One major advantage of using this module is that it is just a question of two resistors and a general purpose transistor of communicate with the microcontroller. This is our interrupter module's circuit diagram.

MOC7811 is an interrupter sensing component, while the rest of the circuit is an interrupter device. The module comprises three wires: Vcc, Signal and field. The module performance is LOW, otherwise it stays HIGH while an interrupt happens. It contains an IR LED mounted in a plastic body with photodiode mounted on each other. The conceptual degree of the picture diode will change immediately

Microcontroller-Based Propeller Clock

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CONCLUSIONS

The insistence of the vision system to create a show was the concept behind this project. We have selected and incorporated our design for a clock. In analogue and digital mode, the clock will operate. Wherever an automated display is required, the project may be useful.

REFERENCES

[1] M. Coltheart. “The Persistence of Vision”, Philos Trans R. Soc. London, B. Biol. Sci., pp. 57-69, Jul. 8 1980. (PMID 6106242).

[2] Muhammed Ali Mazidi, Janice Gillispie Mazidi and Rolin D Mckinlay, The 8051 Microcontroller and Embedded System Using Assembly and C,2nd ed., Pearson 2007.

[3] Official website: Atmel.

[4] K. R. Botkar, Integrated Circuits, 2nded, Khanna Publisher, 2003.

[5] J. B. Gupta, Electronic circuits and devices, 1st ed., S.

K. Kataria and Sons, 2005.

[6] Official Website: Keil Software C51.

a. Software Description

KEIL C51

The 8051 Microcontroller Keil C51 C compiler is the world's most common compiler [6]. It offers more functionality than any current compiler. The C51 Compiler enables 8051 programmes to be written in C that have the reliability and speed of assembling languages until compiled. The C51 compiler language extensions allow you to completely leverage all 8051 tools. The C51 Compiler convert C source files into mobile object modules that contain complete symbolic debugging information with the μ Vision debugger or an emulator in a circuit. The compiler produces, in addition to the object file, a listing file with the choice of the symbolic table and the cross reference information. To type the programme code, we used the Keil compiler. The code is written in C.

RESULTS

· Interrupt Module Testing

This Interrupter module testing was required to detectthe exact position of wheel on which whole circuit assembly is mounted.

Supply voltage given to

PinNo.1(Collector) and Pin No.3 (Anode) ofMOC7811=5.6V.

Output voltage obtained at Pin No.1of MOC 7811without interrupt=5.23V. Output voltage obtained at Pin No.1 of MOC7811 with interrupt = 0.10V.

· Power Supply Module Testing

Power supply module was designed to provide5V DC power supply necessary to drive both motor and circuit. AC input is given from 12V 750mA transformer. Following were the results: Input voltage,

Vs=12V AC. Output voltage, Vo1=11.82V.

DC Output voltage, Vo2= 4.92V DC (observed across 7805)

· Display of Generated Pattern

Vision & Quest, Vol. 9, No. 1, Jan.-June 2019ISSN: 0975-8410

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