Minor Projects


Fastest Finger First Indicator

Quiz-type game shows are increas- ingly becoming popular on tele- vision these days. In such games, fastest finger first indicators (FFFIs) are used to test the player’s reaction time. The player’s designated number is displayed with an audio alarm when the player presses his entry button.


The project circuit presented here determines as to which of the four contestants first pressed the button and locks out the remaining three entries. Simultaneously, an audio alarm and the correct decimal number display of the corresponding contestant are activated. This project circuit design used the digital integrated circuits such latch IC, NAND Gates, Encoder, hex inverter, driver and timer 555 ICs. A 7 segment display used to show decimal number and audio buzzer is activated comprising clock oscillator(555), this oscillator frequency is adjustable by the preset. The circuit employs the regulated power supply of +5 V using 7805 and +12 V for sufficient alarm level. Once the organiser identifies the contestant who pressed the switch first, he disables the audio alarm and at the same time forces the digital display to ‘0’ by pressing reset pushbutton provided here.


This project design can be further enhanced to accomodate more than four contestants With a slight modification.

Automatic Visitor Counter System

This project is aimed to design an automatic person counter system and which also can extend the optimum energy usage. This system is very beneficial in case if we want to count the number of people going to attend a particular event or any function thereby helps in collecting data by counting the number of people .  This is a bidirectional counter circuit hence it also counts the number of people exiting at a particular time.

The project design uses an advance microcontroller interfaced to IR (InfraRed) sensor pairs in order to fulfil the objective of saving a large amount of energy. Each pair consists of 2 sensor pairs placed at a certain distance from one another in the opposite direction. The IR transmitter is used to transmit IR rays straight to the receiver which receives the input and feeds this to the microcontroller. As soon as a person enters the area where the system is placed, it is detected by the IR sensor module and this info is fed to the microcontroller. The microcontroller process this input received. At this time the system also counts the number of people present and increments a counter on each arrival, this count is displayed on a 7 segment display. Similarly when a person approaches to exit, it is also detected by the IR sensor pair accordingly the sensing priority in both sensor, the controller programme makes a decrement  a counter on each departure, this count is also display on a 7 segment display.

The power supply consists a step down transformer 230/12 vac , this ac voltages is converted to dc unregulated voltages by a full wave diode rectifier bridge and further ripple free dc voltages is obtained by a capacitive filter. Further, +5 volt dc regulated supply is generated using a voltage regulator IC 7805 for operation of the circuit.  

Automatic Liquid Level Controller

Monitoring Systems are necessary to understand the changes that take place in environments. Remote monitoring and data collection systems are useful and effective tools to collect information from bulk storage tanks and to monitor the same. The measurement of liquid inside the tank is most important and such systems are useful in industries which are categorized as safety critical systems. This project implement the automatic liquid level controller using a low power microcontroller device and ultrasonic sensor interfaced to display, keypad and dc pump motor driver for tank level monitoring and automatic controlling the pump.

The system hardware includes a high speed, low power microcontroller interfaced to an Ultrasonic sensor to measure the distance of liquid level. A 4X4 metric keypad and LCD display are connected to microcontroller for user setting liquid level. A DC Motor driver is interfaced to drive and auto controlling the pump motor. The important feature of this automatic controller is that user can entered three different level position and when run the pump motor and while liquid level reach to the first bottom level set the speed of pump motor decrease to 33% and so on while reached to 2'nd level  the speed becomes decrease to 66% and at 3'rd final level the pump becomes off. Thus, the automatic liquid level control with respect to different level and time can be achieved as user requirement. There also a buzzer is connected which initiate and alarm on reaching the liquid at user set level.

Further, this system can be enhanced by involving a wireless device such GSM modem, RF modem to the system, so user can monitor the level and also controlling it from any remote place.  

Automatic Home/Office Light Control and Fan Regulation


 The main purpose of this Project is to develop a bidirectional visitor counter’  controls a room light as well as count the number of individuals entering and leaving a room. Also, a fan speed to be regulate automatic based on temperature and number of person in side a room.

  When an individual enters into a room then one counter is incremented by one and one light in a room will be switched ON and when the individuals leaves a room then the counter is decremented by one. When the number of individuals in a room is greater than 5 then 2 lights will be switched ON. When the individuals in a room are more than 10 then 3 lights will be switched ON. Similarly on increase of every 5 individuals one more light will switched ON. Lights will turn OFF when all the individuals go out of a room. The total number of individuals present inside a room is also displayed on the LCD display. IR sensors and microcontroller does above job. IR sensors sense the obstruction and microcontroller receives the signals produced by the obstruction from the sensors. The received signal is operated via program stored in ROM of Microcontroller..

The automatic speed control of fan is also done based on sensing a temperature sensor and number of person inside a room. The design proposed here is appropriate according to the modern lifestyle. The simulation of the system has been done on Proteus Professional Software v 8.0. 

Digital Thermometer using High Temperature Thermocouple

This project is a 4-digit Industrial Digital thermometer based on microcontroller (MCU) and high temperature thermocouple, which can measure temperature up to 1024°C. Normal thermometers have a limited range, and can easily get damaged at very high temperatures. So thermocouples are used in industries for measuring very high temperatures. This circuit uses a K-type thermocouple along with MAX6675 IC for temperature readings.

MAX6675 IC has inbuilt cold-junction compensation (that is, zero temperature reference) and it digitises the signal from a K-type thermocouple. It converts the signal to digital (binary) with an accuracy of 0.25°C. Temperature is displayed on four 7-segment displays (common-anode) without decimal point. The basic principle of a thermocouple is that, if two junctions are exposed to two different temperatures, an emf is generated between the two junctions of two dissimilar metal wires. K-type thermocouples can measure temperatures up to 1300°C, and are widely used in industries for measuring temperatures of furnaces, heaters and the like.

The circuit of this industrial digital thermometer uses ATmega16 MCU, MAX6675 converter, 5V voltage regulator 7805 , four 7-segment displays and a relay with few other components. Initially, when the circuit is switched on, the program makes all four displays glow as a self-test. Then, the displays show an alarm temperature value for a while. Thereafter, the temperature is displayed continuously. While MAX6675 module is capturing temperature value, LED2 blinks continuously. The circuit identifies open-loop condition through the displays. If thermocouple is not properly connected to MAX6675, OPE will be displayed. If there is an error with MAX6675 module, Err will be displayed. The circuit generates an alarm through a buzzer, and a relay gets energised on crossing a pre-determined temperature value. Thus, this circuit regulates the heating device by switching it on or off through the relay. The heat source is connected between COM and NC pins of the relay. The firmware code (MAX6675thermo-meter.c) is written in C and compiled using Atmel Studio.