How to interface 4x4 Keypad with PIC microcontroller

Th3r4p1sT said:

here is a procedure to read from keypad. in C language.

satA...satD means the rows. and sut1...sut4 means columns.

Code:

#define satA P2_0
#define satB P2_1
#define satC P2_2
#define satD P2_3
#define sut1 P2_4
#define sut2 P2_5
#define sut3 P2_6
#define sut4 P2_7

char tus(void)
{	
	char don = ' ';	
	 for (;;)
	 {
	   sut1=0;//1.sutunu kontrol et
		while(!sut1)
		{
			while (satA==0) {while (satA==0) if(satA==1);don='1';}	   
			while (satB==0) {while (satB==0) if(satB==1);don='4';}
			while (satC==0) {while (satC==0) if(satC==1);don='7';}
			while (satD==0) {while (satD==0) if(satD==1);don='C';}
			sut1=1;  	
		}
	
		sut2=0;//2.sutunu kontrol et
		while(!sut2)
		{
			while (satA==0) {while (satA==0) if(satA==1);don='2';}
			while (satB==0) {while (satB==0) if(satB==1);don='5';}
			while (satC==0) {while (satC==0) if(satC==1);don='8';}
			while (satD==0) {while (satD==0) if(satD==1);don='0';}
			sut2=1;
			
		}
		
		sut3=0;//3.sutunu kontrol et
		while(!sut3)
		{
			while (satA==0) {while (satA==0) if(satA==1);don='3';}
			while (satB==0) {while (satB==0) if(satB==1);don='6';}
			while (satC==0) {while (satC==0) if(satC==1);don='9';}
			while (satD==0) {while (satD==0) if(satD==1);don='=';}
			sut3=1;
			
		}
		
		sut4=0;//4.sutunu kontrol et
		while(!sut4)
		{
			while (satA==0) {while (satA==0) if(satA==1);don='/';}
			while (satB==0) {while (satB==0) if(satB==1);don='*';}
			while (satC==0) {while (satC==0) if(satC==1);don='-';}
			while (satD==0) {while (satD==0) if(satD==1);don='+';}
			sut4=1;
		}
	  if(don != ' ') break;
	  }
	 
 	return don;
}

and here is the circuit for those codes.

**broken link removed**

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akoangsimula said:

thanks....i have again a question..how the scrolling be done?example i pressed 1 in the keypad and i have 4 seven segment the output would be 0001 and if i pressed 2 the output woould be 0012..

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Th3r4p1sT said:

u searching for c codes ? i can give some codes but i dont use pic. i use 8051 so they are not same.

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