SATISH CHANDER SG W BIDIRECTIONAL VISITOR COUNTER of each 7-segment display are connected to port P2 of the microcontroller AT89C51 . IS P L A Y CODING: // Program to make a bidirectional visitor counter using IR . Mini Project Report On Digital Visitor counter using Microcontroller . ROOM APPLIANCE CONTROL WITH BIDIRECTIONAL VISITOR COUNTER. This is a simple circuit diagram of bidirectional visitor counter using microcontroller which helps to count the number of people entering or leaving a room.

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The LCD back light pins are connected to 5V and ground as shown in the diagram below: The threshold voltage for a germanium diode is 0.

Automatic bidirectional visitor counter using 8051 microcontroller (AT89C51)

In order for a microprocessor to be used, other components such as memory, or components for receiving and sending data must usign added to it. A customizable microcontroller incorporates a block of digital logic that can be personalized for additional processing capability, peripherals and interfaces that are adapted to the requirements of the application.

In case that program gets “stuck”, zero will not be written in, and counter alone will reset the microcontroller upon achieving its maximum value. It receives the signals from the sensors, and this signal is operated under the control of software which is stored Micro-controller.

One of those is the timer block which is significant to us because it can give us information about time, duration, protocol etc.

When GPIO pins are configured to an input state, they are often used to read sensors or external signals.


Simply stated, we must have some “way” through data goes from one block to another. For working principle, I would have permitted to tell simply. Its equivalent transistors are BC and BC This Code is only visible to Registered users. It supports vieitor kinds of data, from slow mouse inputs to digitized audio and compressed videos also allows hot swapping.

It may use an electromechanical mechanism, or passive or active electronic components.

Microcontroller (AT89C51) based Digital Visitor Counter Project

The voltage divider is the commonly used biasing mode. At each step, the value of the counter is sent to be displayed on the segments. C0G and NP0 negative-positive-zero, i. The diode operates when a voltage signal is applied across its terminals. That was a prerequisite cohnter production of microprocessors, and the first computers were made by adding external peripherals such as memory, input-output lines, timers and other.

While some embedded systems are very sophisticated, many have minimal requirements for memory and program length, with no operating system, and counrer software complexity. So the practical diode characteristics are only close to that of the desired. The other was either a mask programmed ROM from the manufacturer for large series, or a PROM variant which was only programmable once; sometimes this was signified with the designation OTP, standing for “one-time programmable”.

That means, when plugged in, everything configures automatically. Viaitor function is implemented using a pair of Infrared sensors. To overcome this obstacle, we need to introduce one more block called watchdog. Microcontroller outline with basic elements and internal cisitor For a real application, a microcontroller alone is not enough. Electrolytic capacitors can have a very high capacitance, allowing filters made with them to have very low corner frequencies. It has mainly eight relay terminals.


The Atmega is a very popular vounter chip produced by Atmel. BC is an NPN bi-polar junction transistor. Its memory locations are called registers. This is true even in the day time at some places like conference halls or offices where a good brightness levels are desired.

They, along with IR receivers, are commonly used as sensors.

Almost all microcontrollers have at least two different kinds of memory, a non-volatile memory for storing firmware and a read-write memory for temporary data. Microcontrollers are designed for embedded applications, in contrast to the microprocessors usung in personal computer or other general purpose applications consisting of various discrete chips.

At each step, the value of the counter is sent to be displayed on the segments.

The appearance is same as a common LED. When the IR receiver receives signal the potential at the inverting input goes low. This is especially the case in power-supply filters, where they store charge needed to moderate output voltage and current fluctuations in rectifier output. Along with Port 0 used to provide the Bit address for external memory.

With increase in voltage, the firing voltage in forward characteristics is reduced while peak reverse voltage is increased. Skip to main content.