13-11-2012, 04:50 PM
Microcontroller-based Bidirectional Visitor Counter
Microcontroller-based.pdf (Size: 272.29 KB / Downloads: 384)
Visitor counting is simply a
measurement of the visitor
traffic entering and exiting
offices, malls, sports venues, etc.
Counting the visitors helps to maximise
the efficiency and effectiveness of
employees, floor area and sales potential
of an organisation.
the entry/exit point of a company but
has a wide range of applications that
provide information to management
on the volume and flow of people
throughout a location. A primary
method for counting the visitors involves
hiring human auditors to stand
and manually tally the number of visitors
who pass by a certain location. But
human-based data collection comes at
great expense.
Here is a low-cost microcontrollerbased
visitor counter that can be used
to know the number of persons at a
place. All the components required are
readily available in the market and the
circuit is easy to build.
Two IR transmitter-receiver pairs
are used at the passage: one pair
comprising IR transmitter IR TX1 and
receiver phototransistor T1 is installed
at the entry point of the passage, while
the other pair comprising IR transmitter
IR TX2 and phototransistor T2 is
installed at the exit of the passage. The
IR signals from the IR LEDs should
continuously fall on the respective
phototransistors, so proper orientation
of the transmitters and phototransistors
is necessary.
Circuit description
the transmitter-receiver
set-up at the entrance-cum-exit of the
SUNIL KUMAR
Visitor counting is simply a
measurement of the visitor
traffic entering and exiting
offices, malls, sports venues, etc.
Counting the visitors helps to maximise
the efficiency and effectiveness of
employees, floor area and sales potential
of an organisation.
Visitor counting is not limited to passage along with block diagram.
Two similar sections detect interruption
of the IR beam and generate clock
pulse for the microcontroller. The
microcontroller controls counting and
displays the number of persons present
inside the hall.
Fig. 2 shows the circuit of the
microcontroller-based visitor counter,
wherein the transmitter and the
receiver form the IR detection circuit.
Control logic is built around transistors,
operational amplifier LM324 (IC1)
and flip-flop (IC2).
When nobody is passing through
the entry/exit point, the IR beam
continuously falls on phototransistor
T1. Phototransistor T1 conducts and
the high voltage at its emitter drives
transistor T3 into saturation, which
makes pin 3 of comparator N1 low and
finally output pin 1 of comparator N1
is high.