Remote Controlled Switch with Secret Code Lock Project

The project work designed with two microcontroller units is a unique one; it can be used for many applications. The main advantage of using this system is to maintain the privacy, so that un-authorized persons can not operate any electrical gadget or any iron safe (which is equipped with this system) unless they know the password. The new technology implemented in the system is, that the lock can be opened or closed automatically through remote. 

The data transmitting card contains a small keyboard (which is interfaced with microcontroller) generates code, a six digit code corresponding program is prepared for microcontroller, since the program is pre-defined, pass word can not be changed. The data delivered from the controller is modulated with 38 KHz frequency produced by the timer IC, and it is transmitted via infrared LED. The controller accepts all the keys data and transmits as it is. In the receiver this data is decoded with another microcontroller, the data received through 38KHz demodulator is fed to microcontroller, the received data is compared with pre- defined program, if the data is correct then the controller energizes the relay, other wise energizes the alarm,  which indicates that it received wrong code. TSOP 1738 is used as demodulator, this is a miniaturized receiver generally used for remote controlled systems, and the output of this device can be fed to controller directly for decoding.