This document describes a PC-based office communication system that transmits text messages to individual or multiple employees using radio frequency technology. The system includes a transmission module connected to a PC for the employer to send messages, and receiver modules for each employee that display messages on an LCD screen and provide notification of received data. Future enhancements could allow two-way communication and extend intrusion detection capabilities.

1. Dikshya Shree Rath (111ec0154)
Dikshya Routray (111ec0185)
Vishal Mishra (111ec0179)
Jagruti Patel (111ec0182)
Nupur Sahu (111ec0188)
ABSTRACT
This project is a PC based communication tool in office for data (text) transmission
to a individual or multiple users using radio frequency technology.
In most of the offices, if an employer has to convey a message to a particular employee or a
group of employees, he has to call them personally or send the message through a
middleman. But there is a possibility of message to be misinterpreted and there is wastage of
time.
In this proposed system, employer in an office will have a transmission module while the
employees will have one receiver module each. If the employer wants to convey any message
to employees or any particular employee, he can send it through the transmitting module
which is connected to the PC. Receiver section consists of a module which receives the data
and feeds to the microcontroller that displays the message on an LCD. A buzzer is also
interfaced to the microcontroller on the receiver side, which gives intimation that data is

2. received. Adapting this technique one can eliminate the need of a third person for
communication, so that the exact message is delivered to the desired person.
This project in future can be enhanced, by adding a feature of two way
communication between the employer and the employee(s).
FUTURE SCOPE
This system is a rapidly growing field and there are new and improved strategies
popping up all the time. For the most part these systems are all built around the same basic
structure, a central box that monitors several detectors and perimeter guards and sounds an
alarm when any of them are triggered.
This system is best for guiding the perimeter of a house or a business center the points
where an intruder would enter the building. In this system IR sensor is used to detect the
intrusion. Similarly the vibration and temperature sensors recognize vibration disturbances
and accidental fires respectively.
 This system can detect intrusion only at discrete points. This system detection
feature can be extended to scanning a complete area. Thus the intrusion into the building can
be detected with much more efficiently.
The redialing feature can also be incorporated such that if the call is not put forward
the first time, the auto dialer will dial the same number until the call is successfully
completed.
A pre-recorded voice message can delivered to the owner notifying him about the intrusion
into the premises.
The addition of the above discussed advancements certainly builds this project into a
much flexible and reliable security system.

3. BLOCK DIAGRAMS:-

4. TEASERS SOLVED:-
Q: Which microcontroller is used in this project?
A: A 40 pin microcontroller from 8051 family is used in this project.
Q: What is the range of RF?
A: RF range is 50 meters.
Q: What is the frequency it operates at?
A: It operates at a frequency of 315MHz
Q: How is the message transmitted?
A: The message is transmitted through the hyper terminal software, by connecting a PC to the device.
Q: Can this project be implemented without using the hyper terminal?
A: Yes, this project can also be implemented using a GUI application.
HARDWARE
REQUIREMENTS:
8051 series Microcontroller,
Push buttons,
Transformer,
Regulator,
LED, LCD,
Resistors, Capacitor,
RF module, Level Shifter IC,
DB9 connector.
SOFTWARE REQUIREMENTS:
Keil compiler
Languages: Embedded C or Assembly.