With a C program, 

You can for example use a thread which sleeps for 0.2 seconds into a while

    pthread_t tid;
    void* doSomeThing() {
             //execute my command
    int main(void)
        int i = 0;
        int err;
        err = pthread_create(&(tid), NULL, &doSomeThing, NULL);
        if (err != 0)
            printf("\ncan't create thread :[%s]", strerror(err));
            printf("\n Thread created successfully\n");

        return 0;

use it to know how to create a thread : [create a thread][1] (this is the link I've used to paste this code)

  [1]: http://www.thegeekstuff.com/2012/04/create-threads-in-linux/