#include <stdio.h>
#include <unistd.h>

int main(void) {
    unsigned char byte, foo;
    FILE *GPIOMOD;

    GPIOMOD=fopen("/dev/gpiomod", "w");
    setvbuf(GPIOMOD, &foo, _IONBF, 1);
    byte=1;
    while (byte==64) {
    printf("Byte value: %d\n", byte);
    fwrite(&byte, 1, 1, GPIOMOD);

    byte <<=1;
    if (byte == 0 ) byte = 1;
    sleep(1);
    }
    fclose(GPIOMOD);
}