09-10-2010, 04:39 PM
[attachment=5560]
Wireless Electronic Notice Board with Multi Point Receivers
using RF Communication System
IEEE Reference:
Highly Reliable RF Communication System for point to multi point
communication
Vangala, S. Pishro-Nik, H.
Univ. of Massachusetts, Amherst
ABSTRACT
Notice Board is primary thing in any institution / organization or public
utility places like bus stations, railway stations and parks. But sticking various
notices day-to-day is a difficult process. A separate person is required to take
care of this notices display. This project deals about an advanced hi-tech
wireless notice board.
The project is built around the AT89C51 micro controller from Atmel. This
micro controller provides all the functionality of the display and wireless control. It
also takes care of creating different display effects for given text.
Alphanumerical keypad is interfaced to the transmitter to type the data and
transmit. The message can be transmitted to multi point receivers. After entering
the text, the user can disconnect the keyboard. At any time the user can add or
remove or alter the text according to his requirement.
This project uses regulated 5V, 1A power supply. 7805 three terminal
voltage regulator is used for voltage regulation. Bridge type full wave rectifier is
used to rectify the ac out put of secondary of 230/12V step down transformer,
