When a car owner want to lock or unlock his or her car today, it’s preferable done by using a
remote control. The system is really comfortable when the car owner is using the remote.
A problem arises if a thief gets the remote.
The thief doesn’t have to know where the car is parked, an approximate estimation where the
car is parked is enough.
For instance, it’s enough to know which car park the car is parked in. If the thief knows that,
he/she can repeatedly activate the remote control while looking for a car indicating with lights
and sounds.
Because of the fact that a car usually indicates that it has been unlocked by making a short
sound indication, there will be no problem finding the car.
The purpose with this project is to make a prototype which makes it harder for a thief to find
the car. A prototype will demonstrate a possible and alternative solution to today’s system.
To activate the remote control, the user has to press and release a button several times.
Each time the button is pressed a timer will start.
The timer will stop when the button is released. When the system has detected that the button
has been pressed three times, the data with the timer values will be encrypted with the
encryption algorithm TEA. The data will then be sent to the receiver unit. The received data
will be decrypted and compared to pre saved values to see if the data agree.
To be informed of the available system for user identification, a research was made. After
some investigation of different kind of biometrics, the conclusion was made to use just a
button instead of biometrics. Since there was no similar systems to the system I planned to
create, it was fun to create something that hasn’t been used in traditional remote controls.
The whole project is concentrated around two microcontrolers, one send module and a
receiver module for radio communications with 433 MHz on AM.
The microcontrolers are programmed with assembler by using the toolset MPLAB.
The ability to be able to control who should be able to read a message has been a wish for a
long time. That led to different kind of encryption/decryption algorithms. Earlier version of
the encryption algorithms simpl...
