Description
ABSTRACT
The design of the PIC micro-controller LED clock consists of few components that implement a digital clock using analogue display pattern. In this paper the LED clock was designed with 12 red LEDs in the outer circle, 12 green LEDs in the inner circle and four centralized yellow LEDs. The four yellow LEDs were used to count and indicate four minutes in consecutive pattern. The inner 12 green LEDs were used in indicating 0, 5, 10, …, 55, 60/0 minutes while the 12 red outer LEDs were used to indicate 0, 1, 2, …, 11, 12/0 hours respectively. Before the four yellow LEDs count, the first green LED (0 or 60) and first red LED (0 or 12) in circular arrangement were turned ON. After the four yellow LEDs count, the second green LED (5) comes on. This process continues until the twelfth green LED (0 or 60), then the second red LED comes on, and this process continues until the twelfth red LED (0 or 12) comes on. This device was design using micro-controller PIC16F873 with LEDs as the display, which is the aim of this work.
TABLE OF CONTENTS
COVER PAGE
TITLE PAGE
APPROVAL PAGE
DEDICATION
ACKNOWLEDGEMENT
ABSTRACT
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE PROJECT
- OBJECTIVE OF THE PROJECT
- SCOPE OF THE PROJECT
- ADVANTAGES OF DIGITAL CLOCK
- APPLICATION OF THE PROJECT
- LIMITATION OF THE STUDY
- PROJECT ORGANIZATION
CHAPTER TWO
LITERATURE REVIEW
- REVIEW OF THE STUDY
- REVIEW OF DIGITAL CLOCK
- THE HISTORICAL BACKGROUND OF THE STUDY
- DESCRIPTION OF MAJOR COMPONENTS USED
CHAPTER THREE
- MATERIALS AND METHOD
CHAPTER FOUR
- RESULT AND DISCUSSION
CHAPTER FIVE
- CONCLUSION
- RECOMMENDATION
CHAPTER ONE
1.0 INTRODUCTION
1.1 BACKGROUND OF THE STUDY
Time is such a fundamental concept that it is very difficult to define. To measure time is needed something that will repeat itself at regular intervals. The number of intervals counted gives a quantitative measure of the duration. The earliest references for the measurement of the time are the moon and sun. When the sun and the moon were not visible, it was impossible to know the exact time. So, clocks were developed to measure out the hours between checks with the sun and the moon.
The process of measuring time has progressively become more accurate, and the devices more localized ever since. In our modern time, the time is predominately measured by mechanical, and recently by electronic clocks. All clocks measure time, but different clocks can have status or importance.
Many centuries have been spent devising method for the determination and measurement of time. Historically, clocks and watches of all sorts lie at an important crossroads of science, technology and society. Changes in timekeeping technology have influenced the character of scientific.
A clock is an instrument to indicate, keep, and co-ordinate time. The word clock is derived ultimately (via Dutch, Northern French, and Medieval Latin) from the Celtic words clagan and clocca meaning “bell”. A silent instrument missing such a mechanism has traditionally been known as a timepiece [1]. In general usage today a “clock” refers to any device for measuring and displaying the time. Watches and other timepieces that can be carried on one’s person are often distinguished from clocks [2].
Clock is one of the oldest human inventions, meeting the need to consistently measure intervals of time shorter than the natural units: the day, the lunar month, and the year. Devices operating on several physical processes have been used over the millennia [3].
There are two types of clock; analog and digital clock. Analog clocks usually indicate time using angles. Digital clocks display a numeric representation of time. Two numeric display formats are commonly used on digital clocks: 24-hour notation and 12-hour notation. Most digital clocks use electronic mechanisms and LCD, LED, or VFD displays [3].
Analog clocks usually indicate time using angles. The most common clock face uses a fixed numbered dial or dials and moving hand or hands. It usually has a circular scale of 12 hours, which can also serve as a scale of 60 minutes, and 60 seconds if the clock has a second hand. Many other styles and designs have been used throughout the years, including dials divided into 6, 8, 10, and 24 hours. The only other widely used clock face today is the 24 hour analog dial, because of the use of 24 hour time in military organizations and timetables. The 10-hour clock was briefly popular during the French Revolution, when the metric system was applied to time measurement, and an Italian 6 hour clock was developed in the 18th century, presumably to save power (a clock or watch striking 24 times uses more power) [3].
Digital clocks display a numeric representation of time. Two numeric display formats are commonly used on digital clocks:
- the 24-hour notation with hours ranging 00–23;
- the 12-hour notation with AM/PM indicator, with hours indicated as 12AM, followed by 1AM–11AM, followed by 12PM, followed by 1PM–11PM (a notation mostly used in domestic environments) [3].
Most digital clocks use electronic mechanisms and LCD, LED, or VFD displays; many other display technologies are used as well (cathode ray tubes, nixie tubes, etc.). After a reset, battery change or power failure, these clocks without a backup battery or capacitor either start counting from 12:00, or stay at 12:00, often with blinking digits indicating that the time needs to be set. Some newer clocks will reset themselves based on radio or Internet time servers that are tuned to national atomic clocks. Since the advent of digital clocks in the 1960s, the use of analog clocks has declined significantly [3]. Some clocks, called ‘flip clocks’, have digital displays that work mechanically. The digits are painted on sheets of material which are mounted like the pages of a book. Once a minute, a page is turned over to reveal the next digit. These displays are usually easier to read in brightly lit conditions than LCDs or LEDs. Also, they do not go back to 12:00 after a power interruption. Flip clocks generally do not have electronic mechanisms. Usually, they are driven by AC-synchronous motors [3].
1.2 OBJECTIVE OF THE PROJECT
The objective of this project is construct a device that will display the time in seconds, minutes and hours using LED.
1.3 SCOPE OF THE PROJECT
This device was design using micro-controller PIC16F873 with its port pins connected directly to the four yellow LEDs via resistors and the other 12 red and 12 green LEDs were connected to the micro-controller via decoder for pins conservation. Three switches were connected to the micro-controller to set the digital clock.
1.4 ADVANTAGES OF DIGITAL CLOCK
- Even if there is power failure, this clock displays the right time using an inverter.
- Simplicity of the system.
- Accuracy of the system.
1.5 APPLICATION OF THE PROJECT
Because digital clock is very small and inexpensive devices that enhance the popularity of product designs, they are often incorporated into all kinds of devices such as
- Cars
• Radios
• Televisions
1.6 LIMITATION OF THE STUDY
As we all know that no human effort to achieve a set of goals goes without difficulties, certain constraints were encountered in the course of carrying out this project and they are as follows:-
- Difficulty in information collection: I found it too difficult in laying hands of useful information regarding this work and this course me to visit different libraries and internet for solution.
- Difficulty in parts gathering: I found it too difficult when gathering electronics parts used for the prototype.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).
Time Constraint: The researcher will simultaneously engage in this study with other academic work. This consequently will cut down on the time devoted for the research work.
1.7 PROJECT ORGANIZATION
The work is organized as follows: chapter one discuses the introductory part of the work, chapter two presents the literature review of the study, chapter three describes the methods applied, chapter four discusses the results of the work, chapter five summarizes the research outcomes and the recommendations.
CHAPTER FIVE
5.1 CONCLUSIONS
The low cost digital clock with analogue display pattern was design, simulated and implemented. It consists of the switches, PIC16F873 micro-controller, decoders and LEDs. The aim and objectives of developing this project were achieved. The degree of reliability was high because of the few number of components used. The simulation and implementation were successful.
