Simple binary problem

If I highlighted some error register. And print out the converted(decimal to binary) buffers, I got the value I wanted, but the problem is i want to save the value to bin_buffer since I will need them for further process.

My current objective is :

if dec_buffer[1] = 1 ; bin_buffer[1][11] ~ bin_buffer[1][1] = 0 and bin_buffer[1][0] = 1;

if dec_buffer[2] = 2 ; bin_buffer[1][11] ~ bin_buffer[1][2] = 0 , bin_buffer[1][1] = 1; bin_buffer[1][1] = 0;

and soon..

Need some help here :) Thank you :D

# include <stdio.h>
# define BUFFER_NUM_MAX 192  //16*12# define BIT_NUM_MAX 12      //12bit
int dec_buffer;
int bin_buffer;
int bit_num;
int buf_num;
int show_binary(int num){
    int j,b={0};
    printf("data converted: %d ; binary: ",num);
    
    for (j=1;j<=BIT_NUM_MAX;j++){
        b=num%2;
        num=num/2;
    }
    for(j=0;j<BIT_NUM_MAX;j++){
        printf("%d",b);
    }
    printf("\n");
    return b;
}
int main(void){
for (buf_num=1;buf_num<=BUFFER_NUM_MAX;buf_num++){
    dec_buffer = buf_num;    
    /*bin_buffer = */show_binary(dec_buffer);//Error: incompatible types in assignment
}