This project titled "Wireless keypad" The basic idea behind this project is bring the concept of online billing and all features can be done efficiently .In this modern technology the need of all these things has become an important criterion.
The block consists of Keypad Microcontroller FM transmitter FM Receiver, interfacing Circuit, LCD display. The interfacing keypad with the microcontroller or any other devices can be done by two methods through parallel port & Serial port .
Here we are using serial port the data's received from the keyboard are transferred to the microcontroller through the Input/output lines
The ASCII characters are transmitted by the FM Transmitter and FM Receiver present in the microcontroller these data's are transferred through the serial port of the microcontroller.
Once all these procedures these data's are transmitted to the LCD by the Microcontroller. The LCD is connected by the interfacing circuit which connects the Microcontroller eight bit data with the printer cable. This done by the I/O lines of the microcontroller The Controller used here is 89c51.