what is a key fob
Definition of a Home Alarm System:A home alarm system is used as a
defensive device to monitor all unwelcome events such as intrusion, glass breaking and mainly to avoid theft. It is also used to alert a user of a possible danger. It focuses on all of the accessible entry points of the house, so that the alarm
will sound as soon as the intruder enters. In addition, a home alarm system is necessary not just for the material possessions in your home but also increases protection on the family. Furthermore, a burglar may want to break the door of your house while barging in. You also might have to cope with broken windows, smashed furniture and other general damage.
We started off by setting the first four ports of PORTB as the inputs and the latter four ports as the outputs. The first four ports are connected to the columns meanwhile the last four are connected to the rows. Moreover, as a justification for this reasoning is the fact that it is required to scan the columns for the pressed key and then scan the rows and the results will be decoded in a decoder telling us which button of the keypad was pressed. The main functionality of the keypad as mentioned earlier is to set the code. The alarm can be armed and disarmed with a standard four digit user code in our case. The master code is a step above a regular user code.