Automatic Room light Controller with Visitor Counter

Project Cost: 5,200

Project Code: 1101

Download the Synopsis of the project

Description of the project:

Wastage of electricity is one of the main problems which we are facing nowadays. In our homes, schools, colleges, or industry we see that fans/lights are kept on even if there is nobody in the room or area/passage. This happens due to negligence or because we forgot to turn the lights off or when we are in a hurry. To avoid all such situations we have designed this project called “Automatic room light controller with visitor counter”.

This project has two modules:

1. The first one is known as the “Digital Visitor counter”
2. The second module is known as the “Automatic room light controller”.

The main concept behind this project is known as the “Visitor counter” which measures the number of persons entering any room like a seminar hall, conference room, or classroom. This function is implemented using a pair of Infrared sensors. LCD display placed outside the room displays this value of person count. The person count is incremented whenever someone enters the room.

The lights are turned on whenever the person count is greater than zero. And in a reverse way, the person count will be decremented if somebody leaves the room. When the number of persons inside the room is zero, lights inside the room are turned off using a relay interface. In this way Relay performs the operation of the “Automatic room light controller”. Since this project uses 2 infrared sensors, it can be used as a Bidirectional person counter as well.

Video of the Automatic Room light Controller with Visitor Counter

Block Diagram of the Automatic Room light Controller with Visitor Counter project:

Project Photographs:

You will get the following documents with this project:

1. Project Report in pdf format and in word format ( .doc or .docx )
2. Circuit diagram
3. PCB layout
4. Microcontroller Program in assembly language
5. Hex file of the Microcontroller code
6. Datasheets of all the components / ICs used in the project
7. Power point presentation / PPT file

Description in detail:

This is one of the best sensor based projects for final year. And the following are the important modules in this project:

1. IR Transmitter: We have implemented the Person counter module using 2 transmitters and 2 receivers. We have used Infra-Red transmitters. The reason behind choosing IR LED is, that infrared beams are not visible to human eyes and they are not easily triggered by other sources in the environment. The transmitters used are IR LEDs.
2. IR Receiver: We have used the IR sensor as an Infrared receiver. It is an active-low device, which means it gives low output when it receives Infrared rays. So when the IR rays are interrupted by any person then Microcontroller will receive a high pulse from the IR receiver.
3. LCD Display: We have used a 16×2 alphanumeric Liquid Crystal Display (LCD) which means it can display alphabets along with numbers on 2 lines each containing 16 characters. This display should be placed outside the room. It displays various messages like “Person Counter Incremented”, “Person Counter Decremented”, and “No of Person in Room = XYZ” where XYZ is the actual person count.
4. Relay: We have used a 12-volt relay. Since Microcontroller can not turn on the relay directly, we have used a Relay driver circuit. This circuit consists of a transistor which is used to turn on the relay through Microcontroller. We have used an SPDT relay. SPDT means Single Pole Double Throw relay. In this project, we have provided 2 pin connector as an output of Relay. One of these 2 pins is connected to the Normally open terminal of the Relay which is also known as NO contact.
5. Darlington pair: It is used to increase the current gain. The output of 555 IC is given to the Darlington circuit. And the output of the Darlington pair is given to IR led, thus it increases the current through Infrared LEDs which helps in increasing the range of infrared rays emitted from IR LEDs.
6. Microcontroller: This is the CPU (central processing unit) of our project. We have used 89s51 which is a Microcontroller of the 8051 microcontroller family. The various functions of a Microcontroller are like:

• Bidirectional Visitor counter section – It is bidirectional because we have used 2 sensors on a single door. The microcontroller Reads the digital input from two infrared receivers and calculates the number of persons from them.
• Display – The microcontroller sends the person count to LCD so that the person operating this project should read the number of persons inside the room.
• Automatic Room Light controller section – The microcontroller turns on the Room Light when the person count is greater than or equal to one. And turn off the lights when the count is zero. This is done by Relay. Since the relay is used, you can connect an AC bulb or DC bulb as per your requirement. We will provide a bulb holder to connect the AC bulb.

How to give a demo of this project:

• There are 2 transmitters and 2 receivers placed in front of each other. Swap any object (like a mobile) or your fingers (not a single finger) in front of those sensors.
• Then Microcontroller increments or decrements the counter.
• Once the count is non-zero, the room light is turned on using a relay.
• Now swap objects in the reverse direction then the system decrements the count. And room light is turned off once the count becomes zero.

Enhancement added to this project:

We have added a Light Dependent Resistor (LDR) in this project.

Purpose of LDR: Light sensor – LDR will detect the sunlight in the room (or we can say LDR is used to detect daytime)

If there is enough sunlight in the room (which means it is daytime) then the relay will not be turned on even if the person count is greater than zero. In this mode, it will work only as a Person counter to save electricity and works as an energy saver. And if there is insufficient sunlight in the room then only the relay will be turned on so as to turn on the bulb.

Applications of the Automatic Room light Controller with Visitor Counter project:

1. Digital Visitor Counter can be used in various rooms like seminar halls, and conference halls where the capacity of the room is limited and should not be exceeded. The project will display the actual number of persons inside the room.
2. “Automatic Room light Controller with Visitor Counter” can be used in classrooms and study rooms in colleges.
3. The automatic Room light Controller project can also be used in our home because many times we come out of our bedroom or any other room and we forgot to turn off the room light.
4. The Bidirectional person counter project can be used in Cinema halls, multiplexes, malls as well as in temples to count the number of a person entering inside so that these places should not get overcrowded to avoid congestion.

Advantages of the project:

1. The main advantage of this project is that it helps in energy conservation. Because when there is nobody inside the room then the lights are automatically turned off.
2. Human efforts to count the number of persons are eliminated. Since this project does automatic person counting with the help of two sensors installed on the door frame.

Project Future Development:

1. A Voice alarm system can be added to indicate that the room is full & persons can’t enter inside.
2. We can increase the maximum number of persons that can be counted by implementing the external EEPROM IC.
3. We can send this data to a remote location using a mobile or the internet.

How to place these sensors on the door:

Below is the diagrammatic representation of how the two sensors should be placed on the door frame.

Questions and answers about this project:

Question: Why have you used Infrared sensors to count the no of persons? What are the advantages of using Infrared sensors?

Answer: The advantage of using an Infrared sensor is that IR rays are not visible to human eyes. Also, IR rays are not affected by any other sources. For example: If you use LDR as a sensor then it can be easily triggered by sunlight or any other sources of light.

Question: Which type of fan/lights can be controlled using this project? AC or DC?

Answer: We have used Relay to turn on/off the fan or light. So we can use any type of fan/light. We can either use an AC fan or a DC fan as well. Relay provides isolation from the Microcontroller circuit. Thus the user can use a fan operating on a 12 volts (CPU fan) or a 230 volts AC fan.

Question: Suppose two people walk into the room in matching steps interval will it sense one intrusion? i.e. if two-person enter the room without any gap between them then will Microcontroller will detect 2 persons or only 1 person?

Answer: If there is no gap between two persons, then Microcontroller will sense that only 1 person has entered into the room. There should be some time delay (at-least half seconds delay between 2 persons)

Question: Are you using any separate counter IC for counting the persons or Microcontroller itself is configured as the counter?

Answer: We have not used any separate IC for the counting. Microcontroller does all the functions. It is central processing unit for the project. It takes input pulses from sensor, counts the person, activate/deactivates the relay.

Question: How does the counting of people using transmitters & receivers work?

Answer: We have used to 2 pairs of Transmitter and receiver. These should be placed on the door frame, in-front of each other. If a person enters the room then first receiver will cut and then second receiver will cut. Then Microcontroller will increment the count. And if any person leaves the room then second receiver will cut and then first receiver will cut. Then Microcontroller decrements the count.

Question: Concerning pets in the room, are they likely to trigger the system? What are the ways of avoiding false triggering?

Answer: Yes, your Pets can trigger the sensors. To avoid this situation, sensors should be placed at the higher level from ground. You can keep them at 4 feet from ground. But 1 more thing, if your pets jump 4 feet from ground then this will trigger the sensor:-):D1

Question: Can we use an RFID reader & RFID cards in this project along with the Infrared sensors?
Is it possible that in the entry operation, the RFID will count and in the exit operation, the infrared will count?

Answer: Yes, this is possible. We can implement this project using RFID reader.
Whenever person enters the room, he/she will show the RFID card to RFID sensor and the counter will count as one but the infrared entry will not be activated. But when the person is leaving the room, the infrared exit operation will be activated and the counter decrements by one and the lights will turn off if nobody is in the room.
The RFID sensor will be placed outside the room for the Entry and the infrared sensors will be placed at side of the door for the exit operation. Meaning, if the person enters the room and he/she shows the RFID card to RFID sensor, the RFID will activate but it disregards the infrared entry operation. But leaving the room, the infrared will do the task and the counter decrements.

Question: If this project is used during the daytime then lights will always turn on & off and this will lead to a waste of electricity. How to overcome this situation? Or can’t this project be used during the daytime?

Answer: In some specific seminar hall, conference rooms and study rooms, sunlight can not reach in daytime as well. This is to give some presentations on projector or big screens. In these cases lights are turned on even in daytime.
In other cases, where sunlight is enough and lights are not required in day time, we can turn off the project so it will not function. And then we can turn on the project in evening time.

Question: I tried to replicate the circuit of the transmitter and receiver on a breadboard using the given components. The output of both transmitters was adjusted to 38 kHz. But the IR receiver is not giving active low output. What can be the problem?

Answer: Use a potentiometer to adjust the frequency of transmitter circuit. Also check the connections of TSOP1738 IR receiver circuit, sometimes problem could be in receiver.

Question: In this project can we use any sensor other than TSOP1738? Any animal, like a dog, may also enter the room & will get counted by the counter, this will lead to an error. Can u suggest any other sensors which will detect only human beings or a human body?

Answer: TSOP1738 IR sensor is the most suitable sensor for this project.

Question: I have prepared the circuit of the 555 timer IC which is giving an output of 38khz. Problem is that the Red LED connected to the IR receiver is always active (always turned on) and only blinks when I try to cut the infrared beam from the arrangement of the IR transmitter and receiver that you sent me. What can be the problem?

Answer: I have reviewed circuit and have 2 suggestions. First one, Capacitor connected to Pin 5 of IC555 should be 103 pico Farad. And the third terminal of potentiometer RV is left open. It should be connected to second terminal of variable resistor RV. Then set the resistance between pin 7 and 6 to 11.4 kohm. If the circuit is still not working properly then try varying the potentiometer, reduce the resistance. LED should turn off when Transmitter is facing towards Receiver.

Question: Can we get 120 volts as an output of the relay because here in Canada we have lights that work at 120 volts? The transformer works at 240V but here in Canada, we have 120V so do we change the transformer to 120v if yes what transformer do we need? Secondly is it possible for us to remove the transformer and directly supply 9volts to the circuit? If yes then at what point we can connect the DC supply because then we gave to skip the dc converter circuit?

Answer: Relay does not give any voltage output. Relay acts as a switch. About transformer: you can use 9volt/500 milliampere transformer. And if you want to operate this project on regulated DC supply then you can remove transformer and you can directly give 9 volts supply. You have to remove transformer wires and at the same point you can give 9 volt DC supply.

Question: Can this model hypothetically sense whether a person is going in or out of a room? Can the IR sensors detect obstructions only, not the direction?

Answer: Yes, IR sensors detect the direction. This project has 2 sensors. So when person goes in 1st sensor is cut and then 2nd sensor is cut. Thus Microcontroller increments the count. I have added image of how to install sensor on door on this webpage: (see at the end/bottom of page)

Question: Doubt concerning the placement of IR sensor in the door frame. In the website you have given a chart showing the placement of the circuit, in that picture the transmitter1 and receiver2 is on one side of the frame and vice versa. Why is it so? Do you have any specific reason? Can we place TX1 & TX2 on the same side?

Answer: You can place Tx1 & TX2 on same side but it will reduce the efficiency of the receiver as both IR receivers will receive the rays from both transmitters, so if the distance between 2 receivers on one side of door is less then chances are there that it will not identify that person is entering the room.

Question: I too like this project. It’s a very great idea!!! But i have a question. During night time when we go to sleep will the lights be ON or we should TURN OFF it?

Answer: As per the current functionality of the project, lights will be turned on when there is one or more than one person in room. So if you don’t need lights when you are going to sleep, you should turn off the project.

Question: what if i modified this project by adding LDR. so the light will be turn on when the LDR detect darkness. And is the microcontroller need to be programmed ?

Answer: We have provided in the advanced version of this project. LDR will detect the sunlight. So the relay(light) will be turned on when there is darkness. And the microcontroller is pre-programmed.

Question: Does it works for same entry ,exit door..????

Answer: Yes it works for the rooms which has only 1 door for entry and exit.

Question: when a cat or any other animal comes across the IR sensor, will the light remain on or off?

Answer: Sensors does not differentiate between a human being and an animal. So if any animal crosses the sensor then the visitor counter will be incremented or decremented (depending on the direction) and then lights will be turned on if count is greater than zero.

Question: Can you please explain the use of 555 Timer ICs in the project?

Answer: 555 Timer IC is used as a driver circuit for IR LEDs.

Question: What Will happen when the person enters the room and passes through the first sensor but for any reason, he will come back before reaching the second sensor??

Answer: In such cases the counter will not be incremented. There is a waiting period of 5 seconds. If the second sensor is not interrupted within 5 seconds then the waiting period gets over and action is cancelled.

Question: What is the use of a buzzer in this project?

Answer: Buzzer will be turned on when maximum limit of person count has reached. Suppose a seminar hall has seating capacity of 100 then only 100 people should be allowed inside room. Whenever 101th person enters then buzzer should be turned on to indicate that maximum capacity has reached. In this project we have set the limit to 15 for demo purpose.

Question: can we use LDR in this circuit so when sunlight is there lights will remain off

Answer: We have already implemented this part as part of enhancement in our circuit.

Question: Hi sir, this project is almost well for us but I want to know about the disadvantages of this project. Thank sir.

Answer: As mentioned in the description above, limitation can be, “when two people enter without gap in between them, then system will not be able to detect it” and another limitation is of maximum person count which is 255.

Question: Which sensor will be used to differentiate between the human body and the animal body?

Answer: Its quite difficult to get such sensor.