help with this circuit

Thread Starter


Joined Feb 10, 2007
i have provided the Tx and Rx circuit in the attachments.IT is basically the microcontroller 89C51 based Secured Wirless Communication.
This project is used to communicate or transmit a text message from one place to another place through wireless. The text message is encrypted by using the Microcontroller and the encrypted message was transmitted through wireless. At the receiver end the signal was received by the standard receiver and the analog signal was fed to the Microcontroller and it was decrypted by the Microcontroller and the message is displayed over the LCD display. We can use several receivers and the message from the transmitter can be sent to the entire receivers at the same time. Each receiver can be accessed separately by its address.The Microcontroller is used to do the above work. It gets data from the Keyboard and encrypt with a private algorithm and at the receiver end the Microcontroller decrypt it with the same algorithm and display the data over the LCD display.
(in the RX ckt the FM reciever is incorrect its AM reciever- RCR-433 RP )

IN THE CIRCUIT WHAT IS THE USE OF "SEND", "EDIT","RECIEVE" and "READ" pushbuttons ,do you have any idea ? for what purpose are they used ?



Joined Mar 8, 2007
These are keyswitch inputs that can be read by the uC (Microcontroller 89c51), and, the uC program does, I suppose what the key labels suggest. I am not sure whether this is what you had wanted to know.


Joined Apr 20, 2004
Pushbutton inputs to microcontrollers (RESET is the exception) usually have to be handled by the software running the device. So it's up to the programmer about how to interpret the, say, "EDIT" PB input.