Motion Sensor
In managed alarm systems, the control panel also checks the sensors to verify that they are still operational; if a sensor fails to reply, the center alerts the home owner of an out of order sensor. If the home owner activates the alarm system and the control center registers activity in the home, a signal is sent by the control to a buzzer, flashing
lights or any other audiovisual alarm element. Our
design for a functional keypad was the usage of an alternation of ports between inputs and outputs which is done by using the TRIS function. 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. 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.
You may have to play around with the motion sensitivity a bit until you find your optimal setting. It’s better to have your camera point toward a solid background, away from windows. The problem with cameras that can see through glass is that they might pick up plants moving around on a blustery day, or passing vehicles even. Again, if you want to detect motion at a first floor window, then place the camera to one side, not opposite it. This will eliminate two problems at once. The first is that it avoids detecting irrelevant motion.