RESEARCH PAPER ON

MICRO CONTROLLER BASED

REMOTE LOCATOR

Dept of Electronics and Communication Engineering

NITTE MEENAKSHI INSTITUTE OF TECHNOLOGY

Yelahanka, BANGALORE-64

PAPER AUTHORED AND CO-AUTHORED BY:

KAMAL LAMICHHANE

ASHWIN CHAPTE

AVANEE BHAT. M. V

KIRAN. M

(B.E students of ECE, NMIT Bangalore)

INTRODUCTION:

The main aim of this project is to develop a remote device that is used to locate the lost things by sending a signal to small remote units connected to various items in the surroundings such as watches, remotes, keys, TV remotes, purses, eyeglass cases, and cell phones.. Even emergency lights in case of a black out !!

WHAT EXACTLY HAPPENS ??

When the particular thing is lost, the user uses a display to see the listed out objects, finds its predefined code and sends it.

The remote unit attached to the lost item receives the transmitted digital code and produces an alarm to alert the user to locate the thing.

The user can turn the alarm off on the movable device or use a button on the device.

WHY REMOTE LOCATOR SYSTEM ??

Less expensive than wired solutions.

Sophisticated remote locators can be used in

inaccessible areas

Can be used in locations where wired

infrastructure doesn’t exist.

(add more if you can think of anything !!)

HOW IS THIS REMOTE LOCATOR DOING WITH

RESPECT TO GLOBAL USERS??

Research has predicted that the users will almost

triple by 2015 globally !

HARDWARE REQUIREMENTS:

Keypad

Liquid Crystal Display (LCD) screen

8051 Microcontroller

UART cables

RF transmitter and receiver

Buttons or switches

SCHEMATIC BLOCK DIAGRAM OF THE

SUBSYSTEM:

This subsystem has basically got 2 units namely BASE UNIT and REMOTE UNIT.

BASE UNIT INPUTS AND OUTPUTS:

INPUTS:

1. Vcc

2. Keypad

3. On/Off button

4. Alert Button

5. Audible Tone Off button

OUTPUTS:

1. LCD

2. 8051 Microcontroller

3. RF Transmitter

REMOTE UNIT INPUTS:

1. Vcc2. Off button

3. Remote signal

LET’S GET STARTED..

(On the base unit)

When an item is lost, the user scrolls through a

LCD screen. The name of the lost item is found

in the locator menu and the locator button is

then pressed used the keypad.

The locator or the user menu has three modes

of operation:

1. SAVE MODE

2. ALERT MODE

3. LOAD MODE

1. SAVE MODE: This mode is used to designate a code of each thing to

be located and to assign each item to its remote device and then saved in the menu. The codes are entered into the list using KEYPAD.

2. ALERT MODE: The person is then able to scroll through the list of codes

and locate the desired thing, he can then select the item and press the alert to transmit the signal (RF) to each remote unit. The remote devices then receive the transmitted signal and when the correct remote receives the signal, it sounds the alarm on the remote on the particular code.

3. LOAD MODE: When the person wants to add or replace a remote

device in the menu. The added remotes each have a predefined code that is entered into the device and stored so that the device knows what signal to send in order to activate the remote for this new item.

MAIN MENU:

The main menu allows the person to choose

which mode of operation to be used.

The menu is displayed on the LCD and the user

uses the keypad to select the desired mode.

Diagram 4 shows the software flow chart for the

main menu.

SAVE MODE: The LCD prompts the user to choose which remote unit to save

a name to a location.

Then the person uses the keypad to choose which remote to be named and can then use the keypad to enter the desired name.

The 8051 microcontroller then saves the entered name in a module and the LCD goes back to displaying the main menu.

The device which is remote is not used during this mode of operation.

ALERT MODE:

The LCD prompts the user to choose which remote unit is to be found.

The input keypad is used to scroll through the list and choose the name of the desired item to be found.

The 8051 microprocessor repeatedly sends the saved ID number to the RF transmitter.

The circuit of transmitter transmits the RF remote signal to the remote unit receiver circuit.

The receiver circuit then demodulates the received signal and outputs the signal to the decoding circuit.

The decoding circuit determines the ID number and compares it to the predefined number of each remote device.

The remote device that has the matching ID number produces the alarm until the user turns it off on the device or the remote unit itself, using the alarm off switch

LOAD MODE: The LCD prompts the user to choose which remote

unit is being added.

The input device keypad is then used to choose the proper remote unit for loading the data.

After that the LCD prompts the user to enter the new ID number for the remote device, with the help of keypad.

the microcontroller then saves the ID number in a module.

UART CIRCUITRY: (BASE TO REMOTE UNIT)

1. The UART is used to separate the ID number from the

packed serial bit-stream transmitted from the base unit of

the subsystem.

2. The UART finds the beginning and the end of the

transmitted signal and then chucks the start and stop bits

that were added to the ID number before the transmission

of the bits.

3. The UART then carries out the intended ID number (shown

below) to the digital decoding and compare circuitry of

the subsystem.

DIGITAL DECODING OR COMPARING CIRCUITRY

1. The purpose of this circuitry is to determine the

transmitted ID code and to compare this code to

the predefined code of the remote device.

2. ID code is stored in each flip flop of an eight-bit

shift register in order to decode and determine the

ID number code. The output of each flip-flop will be

compared to the predefined number for each

remote device.

3. If each flip-flop output matches the predefined

number code, the circuit produces a high output

else it produces a low output to the tone generating

circuit.

TONE GENERATING CIRCUITRY:

The speaker on the device produces an

audible alert tone when it receives a high input

from the comparator circuitry.

CONCLUSION:

When the particular thing is lost, the user uses a

display to see where the object is.

The code or an identity of the lost item is found

in a predefined list of the lost things.

The remote unit attached to the desired thing

like display or watch receives the transmitted

digital code from the unit and produces an

alarm to alert the user to locate the thing.

Its applications include using sophisticated,

long range remote locators in inaccessible

areas where humans can’t venture.

(ASHWIN ADD MORE IF YOU HAVE ANY!)