Programming

#include <stdio.h>
.............  in your code somewhere:
FILE *out=fopen("/dev/ttyUSB1", "wb");
fwrite("#o1", 3, 1, out);
fclose(out);

fwrite("#o1\n", 4, 1, out);

# Create retrieve.sh
cat <<EOF >retrieve.sh
#!/bin/sh
echo "#o1" > /dev/ttyUSB1
cat /dev/ttyUSB1 > /home/hectormasencio/Desktop/text.txt
EOF
# Set it executable
chmod +x ./retrieve.sh
# Run it
./retrieve.sh

# You now have a file which retrieves data from your microcontroller when you run it.

#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(void)
{
        ssize_t ret;
        char buf[512];
        int fd=open("/dev/ttyUSB1", O_RDWR);
        if(fd < 0) return(1);

        write(fd, "#o1\n", 4);

        while( (ret=read(fd, buf, 512)) > 0)
                write(STDOUT_FILENO, buf, ret);

        close(fd);
        return(0);
}