01-10-2016, 12:24 PM
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Digital visitor counter is a reliable circuit that takes
over the task of counting number of Persons/
Visitors in the Room very accurately. When
somebody enters into the Room then the Counter is
Incremented by one. The total number of Persons
inside the Room is displayed on the seven segment
display module. The microcontroller does the
above job it receives the signals from the sensors,
and this signals operated under the control of
software which is stored in ROM.
It can be used to count the number of persons
entering a hall in the up mode at entrance gate. In
the down mode, it can count the number of persons
leaving the hall by decrementing the count at exit
gate. It can also be used at gates of parking areas
and other public places.
This circuit divided in three parts: sensor, controller
and counter display. The sensor would observe an
interruption and provide an input to the controller
which would run the counter in up/down mode
depending upon the selector setting. The same
count is displayed on a set of 7-segment displays
through the controller.
This project we will create counter system for apply.
The total number of object is displayed on the seven
segment display. The system is fully controlled by the
16 bit microcontroller 8051 which has a 4Kbytes of
ROM for the program memory. It can also be used
at gates of parking areas and other public places.
In this circuit, two infrared (IR) sensor modules are
used each for up and down counting, respectively.
Whenever an interruption is observed by the first IR
sensor, it increments the counter value. Similarly,
when the second sensor detects an obstacle, the
count is decremented. The count value is
calculated depending upon the sensors’ input and
is displayed on a set of four seven segment displays
by using the concept of multiplexing (for concept of
multiplexing refer seven segment multiplexing). The data pins of each 7-segment display are connected
to port P2 of the microcontroller AT89C51. The first
four pins of port P1 (P1^0-P1^3) are connected
to control pins to enable a particular 7-segment.
. P1^5 & P1^6 are configured as input pins at
which the sensors are connected.
The sensor inputs are defined as up and down
selector modes for the counter in the code. Each
time the first sensor is blocked, it gives a high signal
at P1^5 and the count value gets incremented. The
value gets decremented when P1^6, connected to
second sensor, gives high input. At each step, the
value of the counter is sent to be displayed on the
segments.
89C51
89c51 is a low power ,high performance CMOS 8
bit controller with 8K of in system programmable
Flash memory. By combining a versatile 8 bit CPU
within system programmable flash on a monolithic
chip, the atmel AT89c51 is a powerful computer
which provides a high flexibility and cost effective
solutions to many embedded control applications.It
is based on an 8 bit central processing unit with an 8
bit Accumulator and another 8 bit B register as main
processing blocks. Other portions of the
architecture include few 8 bit and 16 bit registers
and 8 bit memory locations. Each 8051 device has
some amount of data RAM built in the device for
internal processing. This area is used for stack
operations and temporary storage of data. This
base architecture is supported with on chip
peripheral functions like I/O ports, timers/counters,
versatile serial communication port. So it is clear
that this 8051 architecture was designed to cater
many real time The following list gives the features
of the 8051 architecture:
• Optimized 8 bit CPU for control
applications.
• Extensive Boolean processing capabilities.