Oct 2011
wireless home security
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. It is used to unlock the system, as well as programming or erasing a regular user code. Theoretically it can also be used to bypass some sensors.