19-07-2011, 08:05 PM
hi can you please provide me the circuit diagram of digital visitor counter at anamikaspcl[at]gmail.com..please consider this request.
19-07-2011, 08:05 PM
hi can you please provide me the circuit diagram of digital visitor counter at anamikaspcl[at]gmail.com..please consider this request.
20-07-2011, 10:22 AM
you can refer these page details of "digital visitor counter"link bellow
https://seminarproject.net/Thread-digita...or-counter
12-06-2013, 11:23 AM
DIGITAL VISITOR COUNTER DIGITAL VISITOR.doc (Size: 380.5 KB / Downloads: 22) Digital Visitor Counter : It 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 LCD. Visitor counting is simply a measurement of the visitor traffic entering and exiting. Offices, malls, sports, venues etc. Counting the visitors helps to maximize the efficiency and effectiveness of employees, floor area and sales potential of an organization. Visitor counting is not limited to 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 sharing human auditors to standard manually tallies the number of visitors who pass by a certain location. But human-based data collection comes at great expense. Here is a low-cost microcontroller based 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. Basic principle : When somebody enters into the room then the counter is incremented by one. The total number of persons inside the room is displayed on LCD .The microcontroller does the above job , it receives the signals from the sensors, and these signals operated under the control of software which is stored in ROM. Microcontroller AT89s52 continuously monitors the sensor, when any object or person passes through the sensor then the light rays falling on the sensor are obstructed, this obstruction is sensed by the Microcontroller. When sensor is obstructed, then the Microcontroller will increment the counter by 1 in the display. Monostable mode : In the monostable mode, the 555 timer acts as a “one-shot” pulse generator. The pulse begins when the 555 timer receives a signal at the trigger input that falls below a third of the voltage supply. The width of the output pulse is determined by the time constant of an RC network, which consists of a capacitor © and a resistor ®. The output pulse ends when the charge on the C equals 2/3 of the supply voltage. The output pulse width can be lengthened or shortened to the need of the specific application by adjusting the values of R and C. Bistable Mode : In bistable mode, the 555 timer acts as a basic flip-flop. The trigger and reset inputs (pins 2 and 4 respectively on a 555) are held high via pull-up resistors while the threshold input (pin 6) is simply grounded. Thus configured, pulling the trigger momentarily to ground acts as a 'set' and transitions the output pin (pin 3) to Vcc (high state). Pulling the reset input to ground acts as a 'reset' and transitions the output pin to ground (low state). No capacitors are required in a bistable configuration. Pins 5 and 7 (control and discharge) are left floating. 3.Astable mode : In astable mode, the 555 timer puts out a continuous stream of rectangular pulses having a specified frequency. Resistor R1 is connected between VCC and the discharge pin (pin 7) and another resistor (R2) is connected between the discharge pin (pin 7), and the trigger (pin 2) and threshold (pin 6) pins that share a common node. Hence the capacitor is charged through R1 and R2, and discharged only through R2, since pin 7 has low impedance to ground during output low intervals of the cycle, therefore discharging the capacitor. REFLECTIVE TWISTED NEMATIC LIQUID CRYSTAL DISPLAY. 1. Polarizing filter film with a vertical axis to polarize light as it enters. 2. Glass substrate with ITO electrodes. The shapes of these electrodes will determine the shapes that will appear when the LCD is turned ON. Vertical ridges etched on the surface are smooth. 3. Twisted nematic liquid crystal. 4. Glass substrate with common electrode film (ITO) with horizontal ridges to line up with the horizontal filter. 5. Polarizing filter film with a horizontal axis to block/pass light. |
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