1.1WIRELESS ELECTRONIC NOTICE BOARD USING R.F:-
Data Security is primary concern for every communication system. There are many ways to provide security data that is being communicated. However, what if the security is assured irrespective of the hackers are from the noise. This Project describes a design of effective security for data communication by designing standard algorithm for encryption and decryption. R.F. is a PAN technology based on the IEEE 802.15.4 standard. Unlike Bluetooth or wireless USB devices, R.F. devices have the ability to form a mesh network between nodes. Meshing is a type of daisy chaining from one device to another. This technique allows the short range of an individual node to be expanded and multiplied, covering a much larger area. The source information is generated by a key pad and this will be encrypted and is sent to destination through R.F. modules. The receiving system will check the data and decrypt according to a specific algorithm and displays on the LCD.This project uses regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac output of secondary of 230/12V step down transformer.
2. LITERATURE SURVEY
2.1 WIRELESS HISTORY:- The wireless era was started by two European scientists, James Clerk Maxwell and Heinrich Rudolf Hertz. In 1984, Maxwell presented the Maxwell’s equations by combining the works of Lorentz, Faraday, Ampere and Gauss. He predicted the propagation of electromagnet waves in free space at the speed of light. His theory was accepted 20 years later, after Hertz validated electromagnetic wave (wireless) propagation. Hertz demonstrated RF generation, propagation and reception in the laboratory. His work then continues by Guglielmo Marconi after 2 decades. He then acquires a method for transmitting and receiving information. Marconi started to commercialize the use of