Matrix [4x4] Keypad interfacing with PIC Microcontroller [ PIC18f2550 ] in Proteus [Step by Step]

 Matrix [4x4] Keypad  interfacing with PIC Microcontroller [ PIC18f2550 ] in Proteus [Step by Step]

Basically a matrix keypad[ 4x4] can be compared as a keyboard of microcontroller .The keypad contains 16 buttons .Internal architecture of keypad described below :

Taken from Internet

You can see  the button's structure  .Here each row is connected with ground through 10k ohm resistor . Now consider that A=1, B=0,C=0,D=0 and column A get +5v .At this situation , if you press   button[A,E]  , the E link get +5v .In this way for button[A,F] , F=+5v or 1, button[A,G] , G=1, button[A,H] , H= 1.

Listen , if we can make ABCD(1000) ,ABCD(0100),ABCD(0010), ABCD(0001) through a loop . Now any button  pressed  , we can uniquely identify the button .In this way the matrix keypad works .

Now Create a project in Proteus :

Proteus Project :

Please follow the steps

I am just trying to make easy for beginner .Now follow the instruction for pick parts from library .

Now pick  PIC18F4550  microcontroller , 22pf capacitor ,crystal , LCD DISPLAY [LM016L] , keypad  from proteus library .Now see the complete circuit given below :

 Matrix [4x4] Keypad  interfacing with PIC Microcontroller [ PIC18f2550 ] in Proteus [Step by Step]

Here i have connected each column with +5v instead of GND and now i am going to provide (1000) ,(0100),(0010),(0001) in each row respectively .So if any button  is pressed we get 0 according to this.

Now We have completed the Circuit and create a project in MikroC .

MikroC Project :

If  you are a beginner , please follow the steps given below :

 

Source Code :

  


  sbit LCD_RS at RB7_bit;  
  sbit LCD_EN at RB6_bit;  
  sbit LCD_D4 at RB5_bit;  
  sbit LCD_D5 at RB4_bit;  
  sbit LCD_D6 at RB3_bit;  
  sbit LCD_D7 at RB2_bit;  
  sbit LCD_RS_Direction at TRISB7_bit;  
  sbit LCD_EN_Direction at TRISB6_bit;  
  sbit LCD_D4_Direction at TRISB5_bit;  
  sbit LCD_D5_Direction at TRISB4_bit;  
  sbit LCD_D6_Direction at TRISB3_bit;  
  sbit LCD_D7_Direction at TRISB2_bit;  
  // End LCD module connections  
  char ch[]="   ";  
  int j=0,ak=0,i=0;  
  void main() {  
  ADCON1=0x0F;  
  CMCON=7;  
  TRISA.F0=1;  
  TRISA.F1=1;  
  TRISA.F2=1;  
  TRISA.F3=1;  
  TRISC.F0=0;  
  TRISC.F1=0;  
  TRISC.F2=0;  
   TRISC.F4=0;  
  Lcd_Init();  
   Lcd_Cmd(_LCD_CLEAR);    // Clear display  
  Lcd_Cmd(_LCD_CURSOR_OFF);  
  delay_ms(200);  
  j=0;  
   while(1){  
    PORTC=0x00;  
    LCD_Out(1,1,"Matrix Keypad");  
    ak=5;  
    delay_ms(200);  
   while (ak==5){  
  PORTC=0x01;       //  
  if(PORTA.F0==1 & PORTA.F1==0 & PORTA.F2==0 & PORTA.F3==0) {  
   ak=2;  
   Lcd_Chr(2,4,'7');  
    ch[j]='7';  
   j++;  
  }  
  if(PORTA.F0==0 & PORTA.F1==1 & PORTA.F2==0 & PORTA.F3==0) {  
   Lcd_Chr(2,4,'4');  
   ak=2;  
    ch[j]='4';  
   j++;  
  }  
  if(PORTA.F0==0 & PORTA.F1==0 & PORTA.F2==1 & PORTA.F3==0) {  
  Lcd_Chr(2,4,'1');  
      ch[j]='1';  
   ak=2;  
   j++;  
  }  
   if(PORTA.F0==0 & PORTA.F1==0 & PORTA.F2==0 & PORTA.F3==1) {  
     Lcd_Chr(2,4,'C');  
    ch[j]='C';  
   ak=2;  
   j++;  
  }  
   PORTC=0x02;  
   if(PORTA.F0==1 & PORTA.F1==0 & PORTA.F2==0 & PORTA.F3==0) {  
   Lcd_Chr(2,4,'8');  
  ch[j]='8';  
   ak=2;  
   j++;  
  }  
  if(PORTA.F0==0 & PORTA.F1==1 & PORTA.F2==0 & PORTA.F3==0) {  
   Lcd_Chr(2,4,'5');  
  ch[j]='5';  
   ak=2;  
   j++;  
  }  
  if(PORTA.F0==0 & PORTA.F1==0 & PORTA.F2==1 & PORTA.F3==0) {  
   Lcd_Chr(2,4,'2');  
  ch[j]='2';  
   ak=2;  
   j++;  
  }  
   if(PORTA.F0==0 & PORTA.F1==0 & PORTA.F2==0 & PORTA.F3==1) {  
    Lcd_Chr(2,4,'0');  
   ch[j]='0';  
   ak=2;  
   j++;  
  }  
  /////////////////////////  
  PORTC=0x04;        //  
   if(PORTA.F0==1 & PORTA.F1==0 & PORTA.F2==0 & PORTA.F3==0) {  
   Lcd_Chr(2,4,'9');  
  ch[j]='9';  
   ak=2;  
   j++;  
  }  
  if(PORTA.F0==0 & PORTA.F1==1 & PORTA.F2==0 & PORTA.F3==0) {  
    Lcd_Chr(2,4,'6');  
   ch[j]='6';  
   ak=2;  
   j++;  
  }  
  if(PORTA.F0==0 & PORTA.F1==0 & PORTA.F2==1 & PORTA.F3==0) {  
    Lcd_Chr(2,4,'3');  
    ch[j]='3';  
   ak=2;  
   j++;  
  }  
   if(PORTA.F0==0 & PORTA.F1==0 & PORTA.F2==0 & PORTA.F3==1) {  
    Lcd_Chr(2,4,'=');  
    ch[j]='=';  
   ak=2;  
   j++;  
  }  
   /////////////////////////  
  PORTC=0x10;        //  
   if(PORTA.F0==1 & PORTA.F1==0 & PORTA.F2==0 & PORTA.F3==0) {  
   Lcd_Chr(2,4,'/');  
  ch[j]='/';  
   ak=2;  
   j++;  
  }  
  if(PORTA.F0==0 & PORTA.F1==1 & PORTA.F2==0 & PORTA.F3==0) {  
    Lcd_Chr(2,4,'*');  
   ch[j]='*';  
   ak=2;  
   j++;  
  }  
  if(PORTA.F0==0 & PORTA.F1==0 & PORTA.F2==1 & PORTA.F3==0) {  
    Lcd_Chr(2,4,'-');  
    ch[j]='-';  
   ak=2;  
   j++;  
  }  
   if(PORTA.F0==0 & PORTA.F1==0 & PORTA.F2==0 & PORTA.F3==1) {  
    Lcd_Chr(2,4,'+');  
    ch[j]='+';  
   ak=2;  
   j++;  
  }  
  }  
   }  
  }  

 Now follow the instructions, how to create .hex file and save .

 Now go to Proteus and Run the Project .

 In this way you will able to interface Keypad with Microcontroller .

Result Video :

Download This Project(Google Drive)

Thank You!

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