MINI PROJECT TITLES FOR FINAL YEAR ELECTRONIC ENGINEERING STUTENDS

ELECTRONIC and EMBEDDED  MINI PROJECTS :

• Virtual wireless dancing bells for classical dancers. 
• Touchscreen based temperature monitoring and control system with graphical LCD. 
• Location driven car music player. (Plays devotional songs near temples, shuts at home etc.)
• GPS based asset/vehicle/animal/child tracking system.
• Microcontroller and Touchscreen based wireless library book catalog system. 
• Touchscreen based Nurse/attendant calling system for physically impaired. 
• Graphical LCD and Memory stick (MMC/SD card) based textbook reading system. 
• Mobile phone controlled four-legged walking robot with speed and direction control. 
• GPS based universal clock. Gets the time from satellites and displays on GLCD. 
• Microcontroller based online examination system with dynamic questions. 
• Digital vehicle speedometer with password enabled speed limit setting.
• GPS based vehicle travel location-logging system. 
• GSM based digital Notice board with display on Monitor or LCD display. 
• PIR based energy conservation system for corporate Computers and lighting system. 
• Remote control of critical software applications with mobile phone. 
• Microcontroller based dual Lithium-ion battery charger with automated charge and discharge cycles. 
• Virtual distance measuring tape with Graphical LCD.
• Radio Frequency wireless remote controlled digital camera with high power LED based focusing light.
• Wireless Speedo meter for boat/ship with speed and location limit alerts. 
• GPS based travel assistant for blind people. 
• Touch Screen based digital devices control system. 
• GSM Mobile phone controlled intelligent Robot. 
• Automatic Intelligent Plant Watering System. 
• DC Motor Speed and direction control over GSM Mobile/Modem. 
• Mobile phone controlled Street Light monitoring and control system. 
• UPS battery monitoring system over GSM for high availability systems (banking/finance/medical etc). 
• Touchscreen controlled lamp dimmer for next generation apartments. 
• Soil Moisture sensor based intelligent irrigation water pump controlling system with GSM technology. 
• DTMF mobile phone controlled dam water gates controlling system with high-level protection. 
• DC Motor Speed and direction control using RF/IR/Zigbee technologies. 
• Hazardous chemical valve control system with stepper motor and line of site remote control. 
• Contact less Motor speed monitoring on Graphical display with high and low speed alerts.
• Liquid dispensing system with adjustable quantity for industrial use. 
• Password enabled pre-paid liquid/milk dispensing system. 
• Wireless Energy Meter monitoring system with automatic tariff calculation. 
• Data logger for energy meter with time and KWH readings. Very useful for historical data logging and analysis. 
• High voltage fuse blown indicator with Voice based announcement system. 
• Voice enabled devices switching for visually impaired. 
• RF transceiver (Zigbee/X-Bee) based energy meter monitoring system. (Energy Meter reading on PC over wireless comm.)
• GSM based SCADA (Supervisory Control and Data Acquisition) implementation. 
• SCADA system design and construction for real-time electrical parameter monitoring and control. 
• Timer based Electrical Oven temperature monitoring and control for Metal Industries. 
• Timer based automatic power cutoff for industrial sealing/packaging machines.
• GPS & GSM Based Car Security System. 
• GPS & GSM Based Realtime Vehicle Tracking System.
• Microcontroller driven GPS Clock (GPS+Microcontroller+LCD) 
• GSM/Mobile/Cell Phone Based Device Monitoring and Control Ststem.
• GSM Based Home Security System.
• GSM Based Automatic Irrigation Water Controller System
• Automatic Intelligent Plant Watering System (Microcontroller + Rain Sensor) 
• Wireless Stepper Motor Controller (Radio Rx/Tx + Stepper Motor + Microcontroller) 
• IR Remote Stepper Motor Controller. Control stepper motor usnig TV remote. (IR Remote + Stepper Motor + Microcontroller) 
• RC5 IR Based Remote Device Switching (IR Remote + Microcontroller + Device Relays)
• Digital Tachometer (Non-contact)
• Digital Frequency Meter (Microcontroller Board + Sensors + LCD) 
• Digital Voltmeter (Microcontroller Board + Sensors + LCD) 
• Real-time SCADA (Microcontroller Board + Sensors + PC Software) 
• Electrical Data(voltage,current,frequency etc..) Logger (SCADA) (Microcontroller Board + Sensors + MMC/SD Memory + PC Sortware) 
• Digital Multimeter (Microcontroller Board + Sensors + LCD)

HOW TO INTERFACE A MATRIX KEYPAD 4X3 TO MICROCONTROLLER 8051(AT89C51) WITH C PROGRAM

Matrix Keyboard interfacing with Micro controller 8051  

      

Keyboards and LCDs are the most widely used input/output devices of the 8051, and a basic understanding of them is essential. In this tutorial the keyboard fundamentals, along with key press and key detection mechanisms was discussed. Interfacing a keyboard with microcontroller 8051 also described here. Keypad is a widely used input device with lots of application in our everyday life. From a simple telephone to keyboard of a computer, ATM, electronic lock, etc., 

keypad is used to take input from the user for further processing. In this article we are interfacing keypad with the MCU AT89C51 and displaying the corresponding number on LCD.  This module can be further used in a number of systems to interfaced keypad with microcontroller and other processors to get desired output. The program to interface keypad with controller is written in C language which is very easy to understand. 

Keypad is organized as a matrix of switches in rows and column. The article uses a 4X3 matrix keypad and a 16x2 LCD for displaying the output of keypad. The circuit diagram shows the connection of keypad with the controller.Port P1 of the microcontroller is used to send the data for displaying on the LCD. P2^1, P2^2, P2^3 pins of microcontroller is connected to RS, RW, EN pins of LCD respectively. Port P3 is used to scan input from the keypad (refer circuit diagram for connection).

      Fig.1 Interfacing matrix keypad with microcontroller 8051

Interfacing the Keyboard to the 8051 :

        At the lowest level, keyboards are organized in a matrix of rows and columns. The CPU accesses both rows and column through ports; therefore, with two 8-bit ports, an 8*8 matrix of keys can be connected to a microprocessor. When a key pressed, a row and column make a connect; otherwise, there is no connection between row and column. In IBM PC keyboards, a single micro controller (consisting of microprocessor, RAM and EPROM, and several ports all on a single chip) takes care of software and hardware interfacing of keyboard. In such systems it is the function of programs stored in the EPROM of micro controller to scan the keys continuously, identify which one has been activated, and present it to the motherboard. In this section we look at the mechanism by which the 8051 scans and identifies the key.

Scanning and identifying the key:      

       

The following Figure shows a 4*4 matrix connected to two ports. The rows are connected to an output port and the columns are connected to an input port. If no key has been pressed, reading the input port will yield 1s for all columns since they are all connected to high (Vcc) If all the rows are grounded and a key is pressed, one of the columns will have 0 since the key pressed provides the path to ground. It is the function of the micro controller to scan the keyboard continuously to detect and identify the key pressed. How it is done is explained next.

The concept of interfacing keypad with the MCU is simple. Every number is assigned two unique parameters, i.e., row and column number (n(R, C) for example 6 (2, 3)). Hence every time a key is pressed the number is identified by detecting the row and column number of the key pressed.

Initially all the rows are set to zero by the controller and the columns are scanned to check if any key is pressed. In case no key is pressed the output of all the columns will be high. 

Whenever a key is pressed the row and column corresponding to the key will get short, resulting in the output of the corresponding column goes to go low (since we have made all the rows zero). This gives the column number of the pressed key.

Once the column number is detected, the controller set’s all the rows to high. Now one by one each row is set to zero by controller and the earlier detected column is checked if it becomes zero. The row corresponding to which the column gets zero is the row number of the digit.  

The above process is very fast and even if the switch is pressed for a very small duration of time the controller can detect the key which is pressed. The controller displays the number corresponding to the row and column on the LCD.

There are IC chips such as National Semiconductors MM74C923 that incorporate keyboard scanning and decoding all in one chip. Such chips use combinations of counters and logic gates (No micro controller).

 Keypad interfacing Embedded C Program:

#include<reg51.h>

#define port P2

#define dataport P1  // Dataport for lcd

#define sec 100

sbit rs = port^1;

sbit rw = port^2;

sbit en = port^3;

sbit col1=P3^4;

sbit col2=P3^5;

sbit col3=P3^6;

sbit row1=P3^0;

sbit row2=P3^1;

sbit row3=P3^2;

sbit row4=P3^3;

void delay(unsigned int msec) //Time delay function

{

int i,j;

for(i=0;i<msec;i++)

for(j=0;j<1275;j++);

}

void lcd_cmd(unsigned char item) //Function to send command to LCD

{

dataport = item;

en=1;

rs= 0;

rw=0;

delay(1);

en=0;

}

void lcd_data(unsigned char disp) //Funtion to send data on LCD

{

dataport = disp;

en=1;

rs= 1;

rw=0;

delay(1);

en=0;

}

lcd_string(unsigned char *disp) // Function to send string on LCD

{

int x;

for(x=0;disp[x]!=0;x++)

{

lcd_data(disp[x]);       

}

}

void lcd_ini()                  //Function to initialize the LCD

  {

    lcd_cmd(0x38);         

    delay(5);

    lcd_cmd(0x0F);       

    delay(5);

          lcd_cmd(0x01);  //clear screen

          delay(5);

    lcd_cmd(0x80);

    delay(5);

   }

void display(int a) //Display functon for LCD

{

 lcd_ini();

switch(a)

{

case 1:lcd_string("one 1");

break;

case 2:lcd_string("two 2");

break;

case 3:lcd_string("three 3");

break;

case 4:lcd_string("four 4");

break;

case 5:lcd_string("five 5");

break;

case 6:lcd_string("six 6");

break;

case 7:lcd_string("seven 7");

break;

case 8:lcd_string("eight 8");

break;

case 9:lcd_string("nine 9");

break;

case 10:lcd_string("zero 0");

break;

case 11:lcd_string("*");

break;

case 12:lcd_string("#");

break;

}

}

void check_col1() //Function for checking column one

{

row1=row2=row3=row4=1;

row1=0;

if(col1==0)           

display(1);

row1=1;

row2=0;

if(col1==0)

display(4);

row2=1;

row3=0;

if(col1==0)

display(7);

row3=1;

row4=0;

if(col1==0)

display(11);

row4=1;

}

void check_col2() //Function for checking column two

{

row1=row2=row3=row4=1;

row1=0;

if(col2==0)

display(2);

row1=1;

row2=0;

if(col2==0)

display(5);

row2=1;

row3=0;

if(col2==0)

display(8);

row3=1;

row4=0;

if(col2==0)

display(0);

row4=1;

}

void check_col3() //Function for checking column three

{

row1=row2=row3=row4=1;

row1=0;

if(col3==0)

display(3);

row1=1;

row2=0;

if(col3==0)

display(6);

row2=1;

row3=0;

if(col3==0)

display(9);

row3=1;

row4=0;

if(col3==0)

display(12);  //For #

row4=1;

}          

void keypad()

{

          row1=row2=row3=row4=0;

          if(col1==0)

          check_col1();

          if(col2==0)

          check_col2();

          if(col3==0)

          check_col3();

}

void main()

{

col1=col2=col3=1;

while(1)

{                

keypad();

 }      

}

 

HOW CONVERT ARRAY OF ELEMENTS INTO DECIMAL VALUE (INTEGER)

Convert Array data to an decimal number

In some programs it is necessary to convert the array elements into an integer value like receive value from keyboard and set the value as input for countdown timer.4x3 or 4x4 matrix keypads will give one key value at one time and LCD Display also display only one number at a time. So  if we need to display keyboard value 5432 you need to convert separate value of 5,4,3,2 into 5432 to set the timer. You can use this program for convert array elements to an integer.

Microcontroller AT89C51:

Microcontroller AT89C51 is at the heart of the circuit. It is a low power, high performance, 8-bit microcontroller with 4 kB of flash programmable and erasable read-only memory (PEROM) used as on-chip program memory, 128 bytes of RAM used as internal data memory, 32 individually programmable input/output (I/O) lines divided into four 8-bit ports, two 16-bit programmable timers/counters, a five-vector two-level interrupt architecture, on-chip oscillator and clock circuitry. A 11.0592MHz crystal (XTAL1) is used to provide basic clock frequency for the microcontroller. Capacitor C3 and resistor R3 form the power-on reset circuit, while push-to-on switch S20 is used for manual reset.

Liquid Crystal Display (LCD):

Liquid crystal display a type of display used in digital watches and many portable computers.LCD displays utilize two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light.

The liquid crystals can be manipulated through an applied electric voltage so that light is allowed to pass or is blocked. By carefully controlling where and what wavelength (color) of light is allowed to pass, the LCD monitor is able to display images. A back light provides LCD monitor’s brightness.Other advances have allowed LCD’s to greatly reduce liquid crystal cell response times. Response time is basically the amount of time it takes for a pixel to “change colors”. In reality response time is the amount of time it takes a liquid crystal cell to go from being active to inactive. Here the LCD is used at both the Transmitter as well as the receiver side. The input which we give to the microcontroller is displayed on the LCD of the transmitter side and the message sent is received at the receiver side which displays at the receiver end of the LCD and the corresponding operation is performed.

They make complicated equipment easier to operate. LCDs come in many shapes and sizes but the most common is the 16 character x 4 line display with no backlight. It requires only 11 connections – eight bits for data (which can be reduced to four if necessary) and three control lines (we have only used two here). It runs off a 5V DC supply and only needs about 1mA of current. The display contrast can be varied by changing the voltage into pin 3 of the display.

 Power Supply Unit

The power supply unit is used to provide constant 5 V dc supply to the peripherals. The 230 V ac is converted into 9 V ac by using a transformer and then a bridge rectifier rectifies it to a 9 V dc with ac ripples. This is then filtered by electrolytic capacitors used across the rectifier output. LM7805 regulator is employed to obtain a constant 5 V dc at the output.

 Convert Array data to an decimal number Program:

 #include<reg51.h>

sfr lcd_data_pin=0xA0;  // data port P2

sbit rs=P3^0; // Register select pin

sbit rw=P3^1; // Read write pin

sbit en=P3^6; // Enable pin

void delay(unsigned int msec)    //delay function

{

int i,j;                                   

for(i=0;i<msec;i++)

for(j=0;j<1275;j++);

}

void lcd_command(unsigned char comm) // function to send command to LCD

{

lcd_data_pin=comm;

en=1;

rs=0;

rw=0;

delay(1);

en=0;

}

void lcd_data(unsigned char disp)    // function to send data on LCD

{

lcd_data_pin=disp;

en=1;

rs=1;

rw=0;

delay(1);

en=0;

}

void main()

{

 unsigned int i,s,test_final,test_final_1,test_final_2,test_final_3,test_final_4,test_final_5;

unsigned int value[4]={5,4,3,2};

while(1)

{

lcd_command(0x38);  

delay(5);

lcd_command(0x0F);      

delay(5);

lcd_command(0x80);

delay(5);

  i=value[0]*1000+value[1]*100+value[2]*10+value[3];

                  test_final=i;               

                  s=test_final/10000;                                               

                   if(s!=0)

                    {

                      lcd_data(s+48);

                       delay(250);

                    }

                   else

                     {                            

                            s=test_final/1000;

                            test_final_1=test_final%1000;

                             test_final_2=test_final_1/100  

                             test_final_3=test_final_1%100;

                              test_final_4=test_final_3/10;

                             test_final_5=test_final_3%10;

                            lcd_data(s+48);

                             lcd_data(test_final_2+48);

                               lcd_data(test_final_4+48);

                                 lcd_data(test_final_5+48);                           

                                                                  

             }                                

    }

}