In this project, the design and implementation of an electronic key holder that can be traced if
lost using an RF based remote unit has been executed. The key holder was designed with an
inbuilt RF receiver that can work within a radius of up to 50m in an open line of sight. A
transmitter has been correspondingly incorporated to send a signal to the receiver circuit and the
receiver produces an alarm sound on receiving the signal. This setup is called an RF module.
The implementation involves a hardware arrangement that is designed in such a way that one of
the components can send a signal and the other component would recognize this signal, receive it
and decode it. The RF module is a small electronic circuit used to transmit and receive a radio
wave on a carrier frequency. In this project a frequency of 433MHz was selected as ideal.
The RF module involved two sub-units called a transmitter and a receiver. A transmitter is used
to transmit data from input. The input signal is converted into a serial data using a HT12E
encoder. The encoded data is transmitted through a wireless media to a receiver a distance away.
The receiver circuit has a decoder that decodes the data into parallel ports using a HT12D
decoder. The decoded signal is used to run the output which in this case is a buzzer at the end of
the decoder. Besides the electronic key holder, the RF module can be used in a number of other
RF based applications such as RFID technology, the wireless mouse, Remote Robot control,
Weather monitoring systems etc. It is therefore fair to say that the versatility and applicability of this project is unquestionable.


Electronic key holder.pdf1.17 MB