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3. Implement Hamming code- Error Correction
Mechanism in C language
Ans:
Aim:
To Implement Hamming Code using C language.
Code:
#include <stdio.h>
int main()
int data[20];
int datarecv[20], c, c1, c2, c4 , c8, i;
printf("Enter 8 bits of data (Burst Errors can't be found)\n");
scanf("%d", &data[12]);
scanf("%d", &data[11]);
scanf("%d", &data[10]);
scanf("%d", &data[9]);
scanf("%d", &data[7]);
scanf("%d", &data[6]);
scanf("%d", &data[5]);
scanf("%d", &data[3]);
data[8] = data[9] ^ data[10]^data[11] ^ data[12];
data[4] = data[5] ^ data[6] ^ data[7] ^ data[12];
data[2] = data[3] ^ data[6] ^ data[7]^ data[10]^ data[11];
data[1] = data[3] ^ data[5] ^ data[7] ^ data[9] ^ data[11];
printf("Redundant Bits are: %d%d%d%d", data[1], data[2],
data[4], data[8]);
printf("\nEncoded data is: ");
for (i = 12 ; i >= 1 ; i-- ) {
printf("%d", data[i]);
printf("\nEnter the received dataword:\n" );
for (i = 12 ;i >= 1 ; i--) {
scanf("%d", &datarecv[i]);
c1 =
datarecv[1]^datarecv[3]^datarecv[5]^datarecv[7]^datarecv[9]^da
tarecv[11];
c2 =
datarecv[2]^datarecv[3]^datarecv[6]^datarecv[7]^datarecv[10]^d
atarecv[11];
c4 =
datarecv[4]^datarecv[5]^datarecv[6]^datarecv[7]^datarecv[12] ;
c8 =
datarecv[8]^datarecv[9]^datarecv[10]^datarecv[11]^datarecv[12]
c = c1 + c22 + c44 + c8*8 ;
if (c == 0){
printf("\nNo Error\n");
} else {
printf("\nError on position %d", c);
printf("\nCorrect Message: ");
if (datarecv[c] == 0)
datarecv[c] = 1;
else
datarecv[c] = 0;
int choice; while(1) { printf("\n1.Find CRC\t2.Check CRC\t3.Exit \nYour choice\t"); scanf("%d",&choice); switch(choice) { case 1: printf("Enter the input string\n"); scanf("%s",text); printf("Enter the key\n"); scanf("%s",key); crc(); printf("the transmitted message is %s\n",strcat(text,rem)); break; case 2: printf("Enter the input string\n"); scanf("%s",&text); printf("Enter the key\n"); scanf("%s",key); crc(); for(i=0;i<strlen(key)-1;i++) if(rem[i]=='1') break; if(i==strlen(key)-1) printf("There is no error in the message\n"); else printf("There is error in the message\n"); break; case 3: exit(0); } } }
Input:
Enter choice: 1. Find CRC
2. Check CRC
If 1 is pressed:
Enter the input string: 101101001
Enter the key: 1011
Output:
The transmitted message is 101101001110
SCREENSHOTS:
5. Implement Checksum- Error Detection Mechanism
in C language.
Aim: To CheckSum using C language: Code: #include<stdio.h> #include<math.h> void sender() { printf("Sender:\n\n"); int a[10],i,m,scheck,rcheck; printf("Enter number of data segments: "); scanf("%d",&m); printf("Enter the data segments:\n"); for(i=0;i<m;i++) scanf("%d",&a[i]); int checksum,sum=0; for(i=0;i<m;i++) sum+=a[i]; checksum=~sum; printf("Checksum: %d\n",checksum); } void receiver() { printf("Reciever:\n\n"); int a[10],i,m,scheck; printf("Enter number of data segments: "); scanf("%d",&m); printf("Enter the data segments:\n"); for(i=0;i<m;i++) scanf("%d",&a[i]); printf("Enter the recieved checksum: "); scanf("%d",&scheck); int checksum,sum=0; for(i=0;i<m;i++) sum+=a[i]; sum=sum+scheck;
checksum=~sum; printf("Checksum: %d\n", checksum); if(checksum==0) printf("No error in transmission\n"); else printf("Error in transmission\n"); } int main() { int a; while(1) { printf("Enter 1 for sender and 2 for reciever. Press 3 to quit\n"); scanf("%d",&a); if(a == 1) sender(); else if(a == 2) receiver(); else if(a == 3) break; else printf("Invalid choice\n"); } return 0; }
Input:
Choose 1 for Sender and 2 for Receiver
If 1:
Sender:
Enter the number of data segments: 4
Enter the data segments: 1001, 1101, 1111, 1000
If 2:
Receiver:
Enter the number of data segments: 4
Enter the data segments: 1001, 1101, 1111, 1000
Enter the Receiver Checksum: -
Output:
Conclusion:
All the error Detecting methods have been implemented using C
language and the output is verified using Pen and paper method
also.
