8051: 16 switch interface code

Description:

            16 switches are connected in this diagram, port2 connected as the 4pin input and 4 pin output.16 switches are connected in matrix method.Port2 connected with switches and port3 blinks the corresponding binary numbers. In this program, r represents row and c represents column, port2 first set as HIGH and the r1 (first row) set as 0 and c1(first column) set 0,and other columns set as 1 the first switch pressed port3 blinks the corresponding binary value and vice versa.

Code:

#include<reg51.h>

sbit r1=P2^0;

sbit r2=P2^1;

sbit r3=P2^2;

sbit r4=P2^3;

sbit c1=P2^4;

sbit c2=P2^5;

sbit c3=P2^6;

sbit c4=P2^7;

void main()

{

            while(1)

            {

                        P2=0XFF;

                        r1=0;

                        while(c1==0&& c2==1&& c3==1&& c4==1)

                        {

                                    P3=1;

                        }

                        while(c2==0&& c1==1&& c3==1&& c4==1)

                        {

                                    P3=2;

                        }

                        while(c3==0&&c1==1&&c2==1&&c4==1)

                        {

                                    P3=3;

                        }

                        while(c4==0 && c1==1&& c2==1&& c3==1)

                        {

                                    P3=4;

                        }

                        P2=0XFF;

                        r2=0;

                        while(c1==0&& c2==1&& c3==1&&c4==1)

                        {

                                    P3=5;

                        }

                        while(c2==0&&c1==1&&c3==1&&c4==1)

                        {

                                    P3=6;

                        }

                        while(c3==0&&c1==1&&c2==1&&c4==1)

                        {

                                    P3=7;

                        }

                        while(c4==0&&c1==1&&c2==1&&c3==1)

                        {

                                    P3=8;

                        }

                        P2=0XFF;

                        r3=0;

                        while(c1==0&& c2==1&& c3==1&&c4==1)

                        {

                                    P3=9;

                        }

                        while(c2==0&&c1==1&&c3==1&&c4==1)

                        {

                                    P3=10;

                        }

                        while(c3==0&&c1==1&&c2==1&&c4==1)

                        {

                                    P3=11;

                        }

                        while(c4==0&&c1==1&&c2==1&&c3==1)

                        {

                                    P3=12;

                        }

                        P2=0XFF;

                        r4=0;

                        while(c1==0&&c2==1&& c3==1&&c4==1)

                        {

                                    P3=13;

                        }

                        while(c2==0&&c1==1&&c3==1&&c4==1)

                        {

                                    P3=14;

                        }

                        while(c3==0&&c1==1&&c2==1&&c4==1)

                        {

                                    P3=15;

                        }

                        while(c4==0&&c1==1&&c2==1&&c3==1)

                        {

                                    P3=16;

                        }                                                                                                             

            }

}

Circuit Diagram: