KEYPAD interfacing with PIC18f4520 problem

[djc]

Hello,

I wrote a program for interfacing 4*4 matrix keypad with PIC18F4520. However when I make particular ROW as zero, it's not getting grounded. I tried it with all the ROW pins .What must be the issue. I am posting code here. Plz guide.

#define ROW0    PORTB.B1
#define ROW1    PORTB.B3
#define ROW2    PORTB.B5
#define ROW3    PORTB.B7
#define COL0    RB0_bit           //For defining PORT as input
#define COL1    RB2_bit           //For defining PORT as input
#define COL2    RB4_bit           //For defining PORT as input
#define COL3    RB6_bit           //For defining PORT as input
#define Select_DS      PORTD.B7       //May only DS,STCP and SHCP pins are used
#define Select_Clk     PORTD.B6
#define Data_DS        PORTD.B5
#define Data_Clk       PORTD.B4


unsigned  int arr_large[16] = {17,125,35,37,77,133,129,61,1,5,17,125,35,37,77,133};
unsigned int  decimalNumber,remainder,quotient,decimalNumber_1,remainder_1,quotient_1;
unsigned int  binaryNumber[100],binaryNumber_1[100],i=1,j,k,l=0,m=0,col,row;

void Key_Detect()
{
     Delay_ms(20);
     quotient = arr_large[l];
           i=1;
                     while(quotient!=0){
                             binaryNumber[i++]= quotient % 2;
                             quotient = quotient / 2;
                             }
                             for(i=i;i<=8;i++)
                             {
                                 binaryNumber[i] = 0;
                             }
                             for(j = i-1;j> 0;j--){
                             Data_DS = binaryNumber[j];
                             Data_Clk = 1;
                             Delay_us(10);
                             Data_Clk = 0;
                             Delay_us(10);
                             }
                 Data_Clk = 1;
                 Delay_us(10);
                 Data_Clk = 0;
                 //Delay_ms(1000);
}

void main ()
{
     TRISD = 0x00;
     TRISB = 0x55;    //Making ROW as output and Column as input    input as high and output as low
     PORTB = 0xff;          //Rows and columns as zero
//     PORTB = 0b11111101;

          Select_DS = 1;            //1
          Select_Clk = 1;
          Select_Clk = 0;

          Select_DS = 0;            //2
          Select_Clk = 1;
          Select_Clk = 0;

          
          Select_DS = 0;            //3
          Select_Clk = 1;
          Select_Clk = 0;

          Select_DS = 0;            //4
          Select_Clk = 1;
          Select_Clk = 0;

          Select_DS = 0;            //5
          Select_Clk = 1;
          Select_Clk = 0;

          Select_DS = 0;            //6
          Select_Clk = 1;
          Select_Clk = 0;

          /*Select_DS = 0;          //7
          Select_Clk = 1;
          Select_Clk = 0;

          Select_DS = 0;          //8
          Select_Clk = 1;
          Select_Clk = 0; */

          Select_Clk = 1;
          Select_Clk = 0;

          
          
      
     //while(1){
     l=0;
     /*do{
        PORTB &= 0xaa; //Ground all the rows at once
        //col = PORTB;
        //col &= 0xaa;  //mask unused bits
        Delay_ms(50);
        }while(PORTB != 0xaa); //wait till all keys released
     do
     {
       do
        {
          PORTB &= 0xaa; //Ground all the rows at once
        //col = PORTB;
        //col &= 0xaa;  //mask unused bits
        Delay_ms(50);
        }while(PORTB == 0xaa); //wait till all keys released
       do
         {
           Delay_ms(50);
           //col = PORTB;
           PORTB &= 0xaa;  //mask unused bits
            }while(PORTB == 0xaa);
       Delay_ms(50);
       PORTB &= 0xaa;
     }while(PORTB == 0xaa);*/
     PORTB.B7 = 0;
     PORTB.B3 = 0;
     PORTB.B5 = 0;

     while(1){
     //ROW0 = 0;
     ROW0 = 0;
     PORTB.B1=0;
     Delay_ms(30);
     //Key_Detect();
     if(COL0==0)
     {
       while(COL0==0)
     {
      Delay_ms(50);
     }
      while(COL0==0)
     {
      Delay_ms(50);
     }
      while(COL0==0)
     {
      Delay_ms(50);
     }
     l=5;
     Key_Detect();
     //break;
     }
     /*while(COL1!=0){
     do{
        Delay_ms(50);
     }while(COL1!=1);
      l=1;
      Key_Detect();
     //break;
     }
     while(COL2!=0){
     do{
        Delay_ms(50);
     }while(COL2!=1);
      l=2;
      Key_Detect();
    // break;
     }
     while(COL3!=0){
     do{
        Delay_ms(50);
     }while(COL3!=1);
     l=3;
      Key_Detect();
     //break;
     }
     
     ROW1 = 0;
     if(COL0==0){
     l=4;
     Key_Detect();
     //break;
     }
     else if(COL1==0){
     l=5;
      Key_Detect();
     //break;
     }
     else if(COL2==0){
     l=6;
      Key_Detect();
     //break;
     }
     else if(COL3==0){
     l=7;
      Key_Detect();
     //break;
     }
     
     ROW2 = 0;
     if(COL0==0){
     l=8;
     Key_Detect();
     //break;
     }
     else if(COL1==0){
     l=9;
      Key_Detect();
     //break;
     }
     else if(COL2==0){
     l=0;
      Key_Detect();
     //break;
     }
     else if(COL3==0){
     l=1;
      Key_Detect();
     //break;
     }
     
     ROW3 = 0;
     if(COL0==0){
     l=2;
     Key_Detect();
     //break;
     }
     else if(COL1==0){
     l=3;
      Key_Detect();
     //break;
     }
     else if(COL2==0){
     l=4;
      Key_Detect();
     //break;
     }
     else if(COL3==0){
     l=5;
      Key_Detect();
     //break;
     }*/


  }
 
}

I am trying for one ROW only, code for rest of the rows are commented.