instrumentation & Controls


Temperature Meter Display

This temperature meter uses the precision micro power centigrade sensor IC LM35. The output voltage of the IC is linearly equal to +10mv per degree centigrade. The temperature level is displayed through LED readout. The circuit uses the precision temperature IC LM35. This three pin transistor like IC give output linearly equal to +10mV per degree rise in temperature. It can measure temperature between -4 degree to +110 degree centigrade. Its related type LM34 is Fahrenheit sensor and its output is equal to -10mV per degree Fahrenheit. Output of IC1 is directly given into the input of the display driver IC LM3914. It is a monolithic integrated circuit with 10 active low outputs that can drive 10 LEDs directly without a current limiting resistor.

The internal circuitry of the IC adjusts the current passing through the LEDs. The input of LM 3914 is very sensitive and its outputs 18 – 10 sinks current one by one as the input receives an increment of 125 milli volts. Here only 6 outputs are used to drive 6 LEDs. More LEDs can be included in the remaining outputs if required. As the IC LM35 senses temperature rise, LEDs one to six light up. If the sensitivity is not high, VR2 can be omitted. Then output of IC LM35 should be directly connected to the input of IC LM3914.

Line Following Robotic Vehicle

This project is aimed to design a robotic vehicle that follows a specific path using a microcontroller. A pair of photo sensors comprising IR transmitter and photo diode is interfaced to the controller to detect the specified path for its movement. Line follower robot is a useful robot that is used in ware houses, industries,  and stores etc, where it follows a dedicated path. This proposed system of a line following robot fulfils the desired functionality and demonstrates the working of it.

 The project design involves an advance microcontroller and a pair of photo sensors, comprising of one IR transmitter and a photo diode in each. It guides the robot to follow a specified path by giving appropriate signal to the microcontroller. Two DC motors are  interfaced to the microcontroller through a motor driver IC. Input signals given to the microcontroller from the sensors and then the controller takes the appropriate action according to the program written in it and drives motors as desired. A rechargeable battery is used here for powering up this robotic vehicle.

 Further the project can be enhanced by adding more advanced sensors to it. This will add more features to the existing project. For example, we can use ultrasonic sensors for detect any obstacle in front of the robot and to take appropriate action.

Wireless and Density based Traffic Signal Light

The project is designed to develop a density based dynamic traffic signal system. The signal timing changes automatically on sensing the traffic density at the junction. Also system involves a wireless Bluetooth technologies for controlling the traffic lights from remote phone at the time of any emergency or unexpected situation. Traffic congestion is a severe problem in many major cities across the world and it has become a nightmare for the commuters in these cities.

Conventional traffic light system is based on fixed time concept allotted to each side of the junction which cannot be varied as per varying traffic density. Junction timings allotted are fixed. Sometimes higher traffic density at one side of the junction demands longer green time as compared to standard allotted time. The proposed system using a microcontroller of AVR family duly interfaced with sensors, changes the junction timing automatically to accommodate movement of vehicles smoothly avoiding unnecessary waiting time at the junction. The sensors used in this project are IR and photodiodes are in line of sight configuration across the loads to detect the density at the traffic signal. The density of the vehicles is measured in three zones i.e., low, medium, high based on which timings are allotted accordingly.

There is a Bluetooth module connected to the microcontroller for wireless remote operating traffic lights from android application operated remote mobile or PC. In any emergencies and unexpected situation the traffic lights signal can be operated according to the traffic situation by authorised person from remote phone or PC.

Auto Attendance Using RFID System

This project is aimedto develop an automatic attendance record system using a radio frequency based RFID system. The RFID tag contains 8 dugut unique identification number, each person is provided a tags with authorized number to swipe over the RFID reader to record their attendance.

Manually attendance takes time also engage a person, In this proposed system, authorized person is given an RFID tag. This tag contains an integrated in built circuit that is used for storing, processing information through modulating and demodulating of the radio frequency signal that is being transmitted. Thus, the data stored in this card is referred as the identification/attendance of the person. Once the person places the card in front of the RFID card reader, it reads the data and verifies it with the data stored in the microcontroller from anadvance series. If the data matches, then it displays a message on the LCD confirming the entry of that person else displays a message denying the attendance. The status of a person’s attendance can be retrieved from this system by pressing the status button interfaced to the microcontroller. The attendance information can be also stored in excel file on PC interfaced a serial communication to the microcontroller running a terminal window software. Hence, a lot of time is saved as all the persons attendance is directly stored in the data base.

The project can be further enhanced by adding features like sending an SMS of the daily attendance of students to their parents. It can also be enhanced by using a finger print module in place of RFID module that has certain drawbacks of tags be misused.

Automatic Toll Tax Collection System

This project is aimed to design an automatic toll-tax collection system for toll gate based on RFID (Radio frequency identification) system using a microcontroller and automatic gate operation. Now a days, streams of traffic are increased and toll gate on highways are congested. It will cause the traffic jam and waste time. The proposed automatic system reduce time consumption for manual transactions and human effort at toll plaza.


The objective of this project is to transform manual transaction to automated toll collection with the help of RFID technology. The project is designed using an advance microcontroller interfaced to a RFID receiver (reader) and motor driver circuit. There are three portions in toll collection system. They are RFID system, balance deduction system and toll gate control system. For the RFID system, 13.56 MHz passive RFID reader and tag pairs are used. The balance deduction system is implemented by an advance Microcontroller. The microcontroller is also used to control gate motor and display the data on the LCD.


A RFID tags provided to vehicle need to be swap over the reader to check the authenticity of vehicle, If the data transmitted by the RF access card matches with the already fed value in the microcontroller wherein check the ID numbers, vehicle numbers and the amount of balance, than only the gate motor interfaced to the microcontroller will start rotating to open the door. Along with that the information of the corresponding vehicle will get displayed on the LCD interfaced to the microcontroller. The new user can register and update the amount of balance via a metric keypad Interfaced to the microcontroller easily.