Design and Construction of Microcontroller Timer Socket Outlet

Design and Construction of Microcontroller Timer Socket Outlet

Chapter One

AIM AND OBJECTIVES OF THE PROJECT

This project aims to;

Design and construct an automatic socket outlet with an operational timer incorporated into it using a microcontroller.

The objectives of this project are as follows:

To conserve electrical power domestically.
To reduce and subsequently prevent electrical hazards in the home front.
To control the use of electrical power domestically.
Through conservation and control of electrical power, electricity bills are reduced.

CHAPTER TWO

LITERATURE REVIEW

BRIEF HISTORY OF MICROPROCESSORS

The first microprocessor was developed by what was then a small company called Intel (short for Integrated Electronics) in the early 1970s. The client, a Japanese company called Busicon, declined to buy the chipset and Intel, faced with a development cost and no customer, decided to market the chipset as a “general purpose” microprocessing system for use in applications where digital logic chips would have been used. The chipset was a success and within a short while, Intel developed a general purpose 4-bit microprocessor called the 4004 [3].

In 1974, the more powerful second generation microprocessor (the 8008) was announced being fabricated as a single chip. This was quickly followed by the Intel 8080. Both the 8008 and the 8080 operated from a single +5v power supply (using NMOS technology).

At about the same time, Motorola released its first microprocessor, the 6800, which was also an 8-bit processor with about the same processing power as that of the Intel 8080. The architectures used in the Intel 8080 and the Motorola 6800 were very different. The Intel 8080 used a register-based architecture with registers AX, BX, CX, DX, and HL, all 16 bit but capable of being used as 8 bit register pairs so that the AX register could be used as two separate registers AH and AL. AH was really just the higher byte of register AX; and AL the lower byte. In this way, the AX, BX, CX, DX, and HL registers could be used as AH, AL, BH, BL, CH, CL, DH, DL, H, and L 8 bit registers [3].

Another thing about the 8080 was its separate I/O map. This meant that to perform byte-wide input/output to hardware, special instructions were used: IN to input from byte-wide input ports, OUT to output to byte-wide output ports. Access to memory involved access to a different memory map using typically the MOV instruction [3].

The Motorola 6800 microprocessor used what is called “Memory Mapped I/O” which means that both memory and byte-wide input/output share the same memory map. The register set was much smaller, consisting of two 8 bit accumulators (A and B) and a 16 bit index register called X. These registers could however support a range of addressing modes which, in effect, made up for the fewer registers (and also made for simpler programming) [3].

To input data from memory or from I/O requires the use of the LDAA instruction, to write data to memory or I/O requires the use of the STAA instruction. Access to the X register was via its own set of instructions, i.e. LDX and STX [3].

Intel and Motorola have maintained the fundamental differences in architecture during the development of later microprocessors [3].

In the case of the Intel range of microprocessors, the 8080 evolved into the 8085 (also 8 bit like the 8080), then the third generation 16 bit 8086 microprocessor which, in its 8088 pseudo 16 bit form, was used in the first IBM PCs. The 8088 was an 8086 but with only an 8 bit data bus. This made it easier to interface to the common 8 bit peripheral devices available at the time. In time, this was followed by the 80186, the 80286, the 800386 (a 32-bit processor), and 80486, leading to the Pentium range of microprocessors (64 bit processors) available today. The 80×86 and Pentium processors have all been designed for use in personal computer type applications and have large memory maps [3].

The Motorola range of microprocessors followed a similar path with the 6800 replaced by the 6809 (8 bit), then the 68000 (16 bit), the 68010, 68020, and 68030 used in many workstations and of course the Apple MAC range of personal computers [3].

CHAPTER THREE

DESIGN ANALYSIS AND CALCULATIONS.

INTRODUCTION

This chapter introduces and explains how various units of the circuit are designed and analysed. The design specification is done with the use of datasheet of some components and mathematical relations derived with the aid of textbooks.

The circuit is divided into four main sections, which are as follows:

Power Supply Unit.
Display Unit
Control Unit
Connection/Operation Unit.

CHAPTER FOUR

CONSTRUCTION, TESTING AND PRINCIPLE OF OPERATION

INTRODUCTION

This chapter introduces and analyses how various components were tested, the standard and calculated values of the components used. It also dwells on the construction, system operation and casing construction. The software program –program debugging, program simulation and program loading are emphasized.

CHAPTER FIVE

CONCLUSION, LIMITATION AND RECOMMENDATION

CONCLUSION

This particular project has taken one through some of the acts of engineering practice which involve; design, construction and testing. The project demonstrates that through the use of devices such as PIC16F877, 7805 voltage regulator and other components used, electrical power usage can be monitored and controlled.

LIMITATIONS

This project has the following limitations:

The maximum allowable time input is ninety-nine minutes.

It only supports 13-amp socket.

The input can only be set in the minute scale.

The buzzer continues to buzz until the system is attended to. This can weaken the backup battery if allowed to buzz for a long period of time.

RECOMMENDATION

The following are recommended for future improvement:

The buzzer should be programmed to buzz for maximum of ten (10) seconds.

Set input of more than ninety-nine minutes.

Set input in ‘seconds’ scale.

REFERENCES

Inderpreet, Kaur (2010) Microcontroller Based Home Automation System With Security, International Journal of Advanced Computer Science and Applications, Vol. 1, No. 6, India.
Raphael, Jr. (2008) “Unplug for Dollars: Stop ‘Vampire Power’ Waste | PCWorld”, PCWorld – Reviews and News on Tech Products, Software and Downloads, Available at http://www.pcworld.com/article/153245/unplug_for_dollars_stop_vampire_power _waste.html [5th December, 2014].
Microcontrollers –A Brief History of Microprocessors –PIC Vietnam [online]; Available at: http://www.picvietnam.com/ [2^ndJanuary, 2015].
IEE Wiring Matters | Spring 2006 | [online]; Available at: http://www.iee.org/ [2^ndJanuary, 2015].

Kolo J. G and Dauda U. S. (2008), Development of a Simple Programmable Control Timer, Leonardo Journal of Sciences, ISSN 1583-0233, pp. 175-186
Morgan J. (1999) Time Management, Mood House Press, California.
Ahmed M. S., Mohammed A. S., Onimole T. G. and Attah P. O. (2006) Design andconstruction of a remote Controlled fan regulator, Leonardo Electronic Journal of Practices and Technologies, Vol. 9, pp. 55-62 [online]. Available at: http://www.lejpt.academicdirect.org/A09/055_062.pdf [2^nd January, 2015]

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