Microcontroller Based Bidirectional Visitor Counter

edifice Microcontroller-bAsed bidirectionAl Visitor prognosticate UMAR SUNIL K ? AkshAy MAthur, kuldeep singh nAglA V isitor calculation is simply a measurement of the visitant traffic entering and exiting finishices, malls, sports venues, and so forth Counting the visitants helps to maximise the efficiency and potence of employees, floor argona and gross sales potential of an organisation.Visitor payoff is not bound to Semiconductors IC1 LM324 quad op-amp IC2 74LS76 J-K transpose IC3 AT89C52 microcontroller IC4 7805 5V regulator T1, T2 L14F1 npn phototransistor T3, T4 2N3904 npn transistor IR TX1, IR TX2 IR transmitting LED BR1 1A straddle rectifier DIS1-DIS3 LTS543 CC 7-segment display Resistors (all ? -watt, 5% carbon) R1, R2 68-ohm R3, R4 6. 8-kilo-ohm R5, R6 100-ohm R7, R8, R10, R11 10-kilo-ohm R9 4. 7-kilo-ohm R12-R32 220-ohm VR1, VR2 20-kilo-ohm preset RNW1 10-kilo-ohm resistor interlocking capacitys C1, C2 C3, C4 C5 C6 C7 miscellaneous XTAL X1 S1 S2 0. F ceramic disk 33pF ceramic disk 10F, 16V electrolytic condenser 470F, 25V electrolytic 0. 1F ceramic disk 12MHz crystal 230V patriarchal to 7. 5V, 250mA secondary transformer Push-to-on switch On/off switch Fig. 1 Transmitter- liquidator set-up at the entrance-cum-exit of the passage Parts List the foundation/exit usher of a company but has a panoptic range of applications that provide info to management on the volume and f meek 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 wretched-cost microcontrollerbased visitor sideboard that fag be apply to know the number of persons at a place. All the offices required atomic number 18 readily ready(prenominal) in the market and the band is easy to build. two IR transmitter-receiver twains are utilis e at the passage one parallel 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 individual phototransistors, so proper preference of the transmitters and phototransistors is necessary. circuit description Fig. 1 shows the transmitter-receiver set-up at the entrance-cum-exit of the passage along with obviate diagram. Two similar sections detect revealion of the IR gibe and produce measure twinkling 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 detective work circuit.Control logic is built around transistors, usable amplifier LM324 (IC1) and reverse (IC2). When nobody is enactment through the entry/exit point, the IR beam continuously go on phototransistor T1. Phototransistor T1 conducts and the high voltage at its emitter drives transistor T3 into saturation, which makes fleur-de-lis 3 of comparator N1 low and finally production signal downfall 1 of comparator N1 is high. Now if soul enters the place, first the IR beam from IR TX1 is calveed and indeed the IR beam from IR TX2. When the beam from IR TX1 is discloseed, phototransistor T1 and transistor T3 cut-off and crepuscule 3 of comparator N1 goes high.The low rig (pin 1) of comparator N1 provides negative bring out beatnik to pin 1 of J-K flip-flop IC2(A). At this moment, the high enter at J and K w w w. e f y m ag . co m 7 8 J a n ua ry 2 0 0 7 e l e c t ro n i c s f o r yo u ConstruCtion w w w. e f y m ag . co m e l e c t ro n i c s f o r yo u J a n ua ry 2 0 0 7 7 9 Fig. 2 Circuit of the microcontroller-based visitor counter ConstruCtion Fig. 3 world-beater supply circuit pins of flip-flop IC2(A) toggles its output to low. On the other hand, the low stimulant at J and K pins of IC2(B) due to Fig. Pin measure pin 1 of configuration of L14F1 and IC2(A) and J intransistor 2N3904 put (pin 9) and K stimulus (pin 12) of IC2(B) are affiliated to pin 1 of comparator N1. The negative-going shiver is utilize to date pin 6 of IC2(B) when the person interrupts the IR beam from IR TX2. in that location is no spay in the output of IC2(B) flip-flop. This triggers the external interrupt INT0 (pin 12) of microcontroller AT89C52. The AT89C52 is an 8-bit microcontroller with 8 kB of flash-based program memory, 256 bytes of RAM, 32 foreplay/output lines, three 16-bit timers/counters, on-chip oscillator and clock circuitry.A 12MHz crystal is utilise for providing clock. behaviors 0, 1 and 2 are tack together for 7-segment displays. Port-0 pin is externally pulled up with 10-kilo-ohm resistor network RNW1 because port0 i s an 8-bit, open-drain, bidirectional, input/output (I/O) port. Port-1 and port-2 are 8-bit bidirectional I/O ports with inside pull-ups (no need of external pull-ups). Port pins 3. 0 and 3. 1 are tack to provide the set pulse to J-K flip-flops IC2(A) and IC2(B), respectively. External interrupts INT0 and INT1 receive the interrupt pulse when the person interrupts the IR beams.Resistor R9 and capacitance C5 provide origin-on-reset pulse to the microcontroller. Switch S1 is used for manual reset. When the microcontroller is re- set, the flip-flops are brought in set state through the microcontroller at packet run time by making their set pin high for a moment. The encourage of the counter increments by Fig. 5 An actual-size, single-side PCB for the microcontroller-based visitor 1 when the counter (Fig. 2) including its index supply (Fig. 3) interrupt service identification number for INT0 is executed.The output of the corresponding J-K flip-flop is set to high again by making its set input pin low through the microcontroller. The micro-controller is configured as a negative-edgetriggered interrupt sensor. Similarly, if somebody exits the place, first the IR beam from IR TX2 is interrupted and then the IR beam from IR TX1. When Fig. 6 Component layout for the PCB the beam from IR TX2 is interrupted, output pin provides clock pulse to pin 6 of J-K 7 of comparator N2 goes low. This flip-flop IC2(B). w w w. e f y m ag . co m 8 0 J a n ua ry 2 0 0 7 e l e c t ro n i c s f o r yo u ConstruCtionAt this moment, the high input at J and K pins of flip-flop IC2(B) toggles its output to low. On the other hand, the low input at J and K pins of IC2(A) due to clock pin 6 of IC2(B) and J input (pin 4) and K input (pin 16) of IC2(A) are connected to pin 7 of comparator N2. The negative-going pulse is applied to clock pin 1 of IC2(A) when the person interrupts the IR beam from IR TX1. There is no change in the output of IC2(A) flip-flop. This triggers the external inte rrupt INT1 (pin 13) of microcontroller AT89C52. The value of the counter decrements by 1 when interrupt service fashion for INT1 is executed.The output of the corresponding J-K flip-flop is set to high again by making its set input pin low through the microcontroller. The circuit is powered by set 5V. Fig. 3 shows the circuit of the power supply. The AC mains is stepped down by transformer X1 to forfeit secondary output of 7. 5V, 250mA, which is rectified by bridge rectifier BR1, filtered by capacitance C6 and regulated by IC 7805 (IC4). Capacitor C7 bypasses any ripple in the regulated output. 3) is shown in Fig. 5 and its component layout in Fig. 6. software The software for the visitor counter is written in C language and compiled employ C51 Keil compiler.The demo version of this compiler is available for free on the website www. keil. com. It can compile programs up to 2 kB only, which is sufficient for writing well-nigh programs. EFY note. The source code and other pert inent files of this article have been include in this months EFY-CD. braid An actual-size, single-side PCB for the microcontroller-based visitor counter (Fig. 2) including its power supply (Fig. visitor. c include int i=0,j,k,l,m,a=63,6,91,79,102,109,125,7,127,111 void enter (void) interrupt 0 i++ if(i999) i=999 P3_1=0 for(m=0mMicrocontroller establish Bidirectional Visitor CounterConstruCtion Microcontroller-bAsed bidirectionAl Visitor counter UMAR SUNIL K ? AkshAy MAthur, kuldeep singh nAglA V isitor 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 Semiconductors IC1 LM324 quad op-amp IC2 74LS76 J-K flip-flop IC3 AT89C52 microcontroller IC4 7805 5V regulator T1, T2 L14F1 npn phototransistor T3, T4 2N3904 npn transistor IR TX1, IR TX2 IR tra nsmitting LED BR1 1A bridge rectifier DIS1-DIS3 LTS543 CC 7-segment display Resistors (all ? -watt, 5% carbon) R1, R2 68-ohm R3, R4 6. 8-kilo-ohm R5, R6 100-ohm R7, R8, R10, R11 10-kilo-ohm R9 4. 7-kilo-ohm R12-R32 220-ohm VR1, VR2 20-kilo-ohm preset RNW1 10-kilo-ohm resistor network Capacitors C1, C2 C3, C4 C5 C6 C7 Miscellaneous XTAL X1 S1 S2 0. F ceramic disk 33pF ceramic disk 10F, 16V electrolytic 470F, 25V electrolytic 0. 1F ceramic disk 12MHz crystal 230V primary to 7. 5V, 250mA secondary transformer Push-to-on switch On/off switch Fig. 1 Transmitter-receiver set-up at the entrance-cum-exit of the passage Parts List the entry/exit point of a company but has a wide range of applications that provide information to management on the volume and proceed 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 c ollection 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 Fig. 1 shows the transmitter-receiver set-up at the entrance-cum-exit of the passage along with block diagram. Two similar sections detect abatement of the IR beam and generate clock pulse for the microcontroller. The microcontroller controls counting and displa ys 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. Now if someone enters the place, first the IR beam from IR TX1 is interrupted and then the IR beam from IR TX2. When the beam from IR TX1 is interrupted, phototransistor T1 and transistor T3 cut-off and pin 3 of comparator N1 goes high.The low output (pin 1) of comparator N1 provides negative trigger pulse to pin 1 of J-K flip-flop IC2(A). At this moment, the high input at J and K w w w. e f y m ag . co m 7 8 J a n ua ry 2 0 0 7 e l e c t ro n i c s f o r yo u ConstruCtion w w w. e f y m ag . co m e l e c t ro n i c s f o r yo u J a n ua ry 2 0 0 7 7 9 Fig. 2 Circuit of the microcontroller-based visitor counter ConstruCtion Fig. 3 Power supply circuit pins of flip-flop IC2(A) toggles its output to low. On the other hand, the low input at J and K pins of IC2(B) due to Fig. Pin clock pin 1 of configuration of L14F1 and IC2(A) and J intransistor 2N3904 put (pin 9) and K input (pin 12) of IC2(B) are connected to pin 1 of comparator N1. The negative-going pulse is applied to clock pin 6 of IC2(B) when the person interrupts the IR beam from IR TX2. There is no change in the output of IC2(B) flip-flop. This triggers the external interrupt INT0 (pin 12) of microcontroller AT89C52. The AT89C52 is an 8-bit microcontroller with 8 kB of flash-based program memory, 256 bytes of RAM, 32 input/output lines, three 16-bit timers/counters, on-chip oscillator and clock circuitry.A 12MHz crystal i s used for providing clock. Ports 0, 1 and 2 are configured for 7-segment displays. Port-0 pin is externally pulled up with 10-kilo-ohm resistor network RNW1 because port0 is an 8-bit, open-drain, bidirectional, input/output (I/O) port. Port-1 and port-2 are 8-bit bidirectional I/O ports with internal pull-ups (no need of external pull-ups). Port pins 3. 0 and 3. 1 are configured to provide the set pulse to J-K flip-flops IC2(A) and IC2(B), respectively. External interrupts INT0 and INT1 receive the interrupt pulse when the person interrupts the IR beams.Resistor R9 and capacitor C5 provide power-on-reset pulse to the microcontroller. Switch S1 is used for manual reset. When the microcontroller is re- set, the flip-flops are brought in set state through the microcontroller at software run time by making their set pin high for a moment. The value of the counter increments by Fig. 5 An actual-size, single-side PCB for the microcontroller-based visitor 1 when the counter (Fig. 2) inclu ding its power supply (Fig. 3) interrupt service routine for INT0 is executed.The output of the corresponding J-K flip-flop is set to high again by making its set input pin low through the microcontroller. The micro-controller is configured as a negative-edgetriggered interrupt sensor. Similarly, if somebody exits the place, first the IR beam from IR TX2 is interrupted and then the IR beam from IR TX1. When Fig. 6 Component layout for the PCB the beam from IR TX2 is interrupted, output pin provides clock pulse to pin 6 of J-K 7 of comparator N2 goes low. This flip-flop IC2(B). w w w. e f y m ag . co m 8 0 J a n ua ry 2 0 0 7 e l e c t ro n i c s f o r yo u ConstruCtionAt this moment, the high input at J and K pins of flip-flop IC2(B) toggles its output to low. On the other hand, the low input at J and K pins of IC2(A) due to clock pin 6 of IC2(B) and J input (pin 4) and K input (pin 16) of IC2(A) are connected to pin 7 of comparator N2. The negative-going pulse is applied to clock pin 1 of IC2(A) when the person interrupts the IR beam from IR TX1. There is no change in the output of IC2(A) flip-flop. This triggers the external interrupt INT1 (pin 13) of microcontroller AT89C52. The value of the counter decrements by 1 when interrupt service routine for INT1 is executed.The output of the corresponding J-K flip-flop is set to high again by making its set input pin low through the microcontroller. The circuit is powered by regulated 5V. Fig. 3 shows the circuit of the power supply. The AC mains is stepped down by transformer X1 to deliver secondary output of 7. 5V, 250mA, which is rectified by bridge rectifier BR1, filtered by capacitor C6 and regulated by IC 7805 (IC4). Capacitor C7 bypasses any ripple in the regulated output. 3) is shown in Fig. 5 and its component layout in Fig. 6. software The software for the visitor counter is written in C language and compiled using C51 Keil compiler.The demo version of this compiler is available for free on the website www. keil. com. It can compile programs up to 2 kB only, which is sufficient for writing most programs. EFY note. The source code and other relevant files of this article have been included in this months EFY-CD. construction An actual-size, single-side PCB for the microcontroller-based visitor counter (Fig. 2) including its power supply (Fig. visitor. c include int i=0,j,k,l,m,a=63,6,91,79,102,109,125,7,127,111 void enter (void) interrupt 0 i++ if(i999) i=999 P3_1=0 for(m=0m