User manual

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4.2 DISCUSSION
4.2.1 Possibilities that need to be considered
During this project, there are many possibilities need to be considered. There are a
few conditions that take to consideration:
1. Someone swings their arms as they walk in.
Since the sensors are mounted at the around 140cm above the floor, it eliminates
most of the problems that would occur from this. In order to prevent the counter
from detect another object with similar shaped and their torso as another, the both
beams have to be broken for a minimum amount of time or the count will be
cancelled. The thickness of the average torso from the side is guaranteed that
both beams will be broken for this minimum amount of time given if a visitor
walks at a normal pace. The minimum time needed for both sensors to be covered
is 0.5 second. This configurable via network commands is saved in the PIC
18F452 flash memory.
2. Someone enters the doorway and stands there.
In this stage, counter will count it as error. Either sensor 1 or sensor 2 or both of
them detects an object for more than 0.5 second, error will occur. This condition
considered for a person that is stand close to either one of the sensor or both of
them and they not moving. A buzzer will beep as along the error is detected.